AMERICAN JOURNAL OF EPIDEMIOLOGY
Copynght © 1976 by The Johns Hopkins University School of Hygiene and Public Health
Vol 103, No 4 Printed in U SA.
RECENT TRENDS IN VIOLENT DEATHS AMONG YOUNG ADULTS IN THE UNITED STATES NOEL S. WEISS Weiss, N. S. (Department of Epidemiology and International Health. School of Public Health and Community Medicine, U. of Washington SC-36. Seattle, WA 98195). Recent trends in violent deaths among young adults in the United States. AmJ Epidemiol 103:416-422.1976. Those Americans who feel that theirs has become an increasingly violent society have support for that belief in recent mortality statistics. Since 1960, death rates in the United States among young adults from motor vehicle accidents, homicide, and suicide have increased dramatically. As of 1973, homicide and suicide rates have shown no indication of leveling off. Death rates from nonviolent causes among young adults, however, are declining, particularly among nonwhite females. accidents, traffic; homicide; mortality; suicide
Among 15- to 34-year-old white males, the rates ceased to increase about 1969, after which they stabilized at the new high levels. Among white males 35-44 years of age the increases following 1960 tended to be small, and by 1973 there was some reduction toward the rates of earlier years. The pattern for white females was similar to that for white males, except that the mortality rise after 1960 was largely confined to the 15- to 24-year group. Death rates for nonwhite males continued their steep climb through 1969, after which there has been a steady decline. Despite this encouraging trend of the last several years, for each age group the death rate was still higher in 1973 than in 1960. For nonwhite females ages 15-24 mortality rates show no definite trend since 1960. For 25- to 44year-olds, however, a steady reduction during the entire interval has taken place, so RESULTS that mortality levels in 1973 were 75-80 per Table 1 presents death rates by race, sex, cent those of 1960. Violent deaths, i.e., those from acciand 5-year age groups from 1960 to 1973. dents, homicide and suicide, account for Received for publication October 6, 1975, and in over 40 per cent of deaths in the 15- to final form November 4, 1975 44-year age group. Substantial increases in Department of Epidemiology and International violent deaths have been shown to repreHealth, School of Public Health and Community Medicine, University of Washington SC-36, Seattle, sent an important factor in the overall WA 98195. mortality rise among young adults between INTRODUCTION
From the initiation of vital statistics records in the United States until about 1960, mortality among young adults (15-44 years of age) had consistently declined. From 1960 to 1968, however, death rates for this age group leveled off and, for males, actually began to rise (1). Increased motor vehicle accident, homicide and suicide rates were an important factor in every color-sex group, although mortality from nonviolent causes among nonwhite males also rose sharply. The present analysis was undertaken to determine what further changes in mortality have occurred in the 5 years between 1968 and 1973. The sources of the data are published and unpublished rates assembled by the National Center for Health Statistics.
416
417
TRENDS IN VIOLENT DEATHS AMONG YOUNG ADULTS TABLE 1
Death rates per 100,000 population among persons ages 15-44 years, by race, sex, and age United States, 1960, 1965, and 1968-1973 Age l l A C c , SCX
White males 1960 1965 1968 1969 1970 1971 1972' 1973 White females 1960 1965 1968 1969 1970 1971 1972* 1973 Nonwhite males 1960 1965 1968 1969 1970 1971 1972* 1973 Nonwhite females 1960 1965 1968 1969 1970 1971 1972* 1973
16-19
20-24
26-29
30-34
35-39
40-44
125.2 130.8 146.8 153.7 147 1 148.1 151.4 156.6
166.9 1719 196.6 202.3 199.0 188.5 192.7 198.6
152.1 157 0 167.1 172 7 169.2 168 1 167 6 173.3
173.2 179 3 182.7 184.4 185.4 181.9 178.7 182.7
240 2 257.4 264 5 265.1 260 4 257.0 246 6 252.1
416.9 411.4 420.7 424.5 420.0 407.0 399.6 394.3
50.2 50.1 57.4 58.7 57.8 57 6 58.3 57 9
60.4 63.3 645 65.7 657 63.1 643 62.4
71.5 70.0 70.9 71.1 73 1 73.3 696 69.1
97.1 101.7 96.3 987 972 94.4 95 0 91.5
147 5 151 3 152 3 152.8 150.9 142 5 142 6 140 7
237.9 2353 2399 240.8 232.0 233.4 228.9 221.8
165 8 168.9 214 6 235 8 224 0 218 4 208.6 190.2
274 8 2886 3659 394.3 415.5 434.3 416 8 384.6
343.0 392.9 454.9 455.2 456 6 493.6 472.2 474 7
428.6 479 6 593.9 589.5 5588 541.6 562 4 526.1
599.2 6865 772 1 788 1 723 7 740.1 747 0 705.4
876 5 936.3 1067 4 1080 9 1024 3 965.6 9904 925.6
804 78.8 81 3 94.7 847 90.0 79.0 79 6
135 7 125.7 138 4 135 8 138 1 137 5 133 1 132.4
210.2 194 0 200.5 192.0 185.2 180.8 176.0 161.6
307.8 3016 3034 293.9 250.0 258.8 244 8 230.9
448 1 442.8 4484 435.0 395 7 3987 3617 3547
6608 636.8 642 3 613 0 5863 562.6 5505 525 7
* Rates based on 50% sample of deaths.
1960 and 1968 (1). Thus, these causes have been singled out here for a closer look. Figures 1-4 present race and sex-specific mortality rates among persons 15-44 years of age for motor vehicle accidents, other accidents, homicide, and suicide, respectively. Because of the pronounced change in the age structure of the 15- to 44-yearold population between 1960 and 1973, the rates have been age-adjusted. The direct method was used; the total 15- to 44-year-
old 1960 population was arbitrarily chosen as the standard. Motor vehicle accident mortality increased, depending on the race and sex group, by 25 to 50 per cent during the 1960's (figure 1). Rates rose substantially both for pedestrian and non-pedestrian accidents. Beginning in 1970, however, motor vehicle accident mortality among males dipped and that among females leveled off. The high male/female mortal-
418
NOEL S WEISS IIIL
70-
130-
——
1.
M_l
-
^
.
Hfwiwhitp Urdfn;
/
White Femoles
60-
\
120/
50-
110i i
White Males Nonwhrte Males While Females Nonwhrte Females
30-
100-
/ /
o
V
/
\ k
Ax /
4
i
i
i
I i
90QJ
i
S 20-1
\
i i
t 1 1
I i
s 80-
s 70» •
• •
I960
1970
1965
20-
...
- • '*
•»••
Year
FIGURE 1 Age-adjusted death rates from motor vehicle accidents among persons 15-44 years of age, by race and sex United States, 1960, 1965, and 1968-1973
10-
I960
1965
1970
Year
FIGURE 3 Age-adjusted homicide rates among persons 15-44 years of age, by race and sex- United States, 1960, 1965 and 1968-1973. 60-
•
§50-
'—•« white males
•--—--•
Nonwfute motes
• — —••
White females
•
Nonwhite females
per
•
§30§20-
10-
I960
1965
1970 Year
FIGURE 2 Age-adjusted death rates from accidents (other than motor vehicle) among persons 15-44 years of age, by race and sex United States, 1960, 1965, and 1968-1973.
ity ratio was present at all years. The annual number of miles traveled by motor vehicles in the United States increased by 50 per cent between 1960 and 1970 and, in contrast to the motor vehicle accident death rate, continued to rise steadily through 1973 (2). What did level off in the early 1970's, however, was the average vehicle speed (2). Death rates from other types of accidents remained relatively stationary for each of the race and sex groups during the 1960-1973 interval (figure 2); rates for nonwhite males rose somewhat during the 1960's, but have fallen again since 1970. Figure 3 depicts the alarming situation with respect to homicide, as rates in all groups increased during the 1960's and continued to do so in the early 1970's. The increase was greatest for males and, though
TRENDS IN VIOLENT DEATHS AMONG YOUNG ADULTS
20-
White Molts Nonwtote Moles White Females Nonwhite Femoles
IO J
s I960
1965
1970 Year
FIGURE 4. Age-adjusted suicide rates among persons 15-44 years of age, by race and sex- United States, 1960, 1966, and 1968-1973.
the relative change was approximately the same in whites and nonwhites, because nonwhite males had by far the highest homicide rate initially they experienced the greatest absolute increase. Between 1960 and 1973, the annual difference in the homicide rate between nonwhite and white males rose from 61.3 per 100,000 to 107.7 per 100,000. In 1973, homicide rates for nonwhite males were about 10 times the rate for white males and more than 30 times the rate for white females. Each of the 5-year age subgroups in the 15-44 year range of the nonwhite male population shared in the rapid increase. Homicide resulting from use of firearms and explosives accounted for the large majority of the rising rates during this period (table 2), and among nonwhites homicide not involving firearms actually declined slightly. Suicide rates have also been increasing among young adults (figure 4); between 1960 and 1973, there was an increase of approximately 25 per cent for each of the four race-sex groups. The two most common means of committing suicide, by poisoning and the use of firearms, showed the largest relative increases during the interval. In every year suicide among whites and males was more common than among nonwhites and females.
419
Perhaps the only encouraging aspect of these statistics is found in figure 5, which presents the trends in mortality for causes other than accidents, homicide or suicide. These rates are currently declining among all groups in the 15- to 44-year age range. White females have the lowest rate of all, one that has slowly but persistently fallen since 1960. During the 1960's white male mortality from nonviolent causes was stable, but a small decline has occurred since 1970. The rate for nonwhite females has fallen more dramatically than the others; the fall is particularly precipitous after 1968. Their mortality from nonviolent causes in 1973 was 28 per cent lower than in 1960. Even the rate for nonwhite males, which in the 1960's rose for the first time, has declined steadily in the early 1970's. DISCUSSION
Limitations of the data There are a number of known limitations and inaccuracies in the rates presented here. The magnitude of each can be fairly well approximated, and none is great enough to materially affect the interpretation of the results. They are detailed as follows. Numerator. Military or civilian deaths which occurred outside the US were excluded from the rates for all of the years. The only deaths resulting from the war in Southeast Asia included here were in persons who survived their injuries long enough so that death occurred in the US. These deaths have to a very small extent inflated the "all-cause" rates for men in the late 1960's and early 1970's. In 1970, for instance, there were 32 such deaths (coded to "Injury resulting from operations of war" (E990-E999)) among men in this age group, corresponding to but 0.03 per cent of the total. Deaths occurring among nonresidents of the US were included in the computation of the rates through 1969, after which they were excluded. However, these accounted
420
NOEL S WEISS TABLE 2
Homicide rates* per 100,000 population among persons ages 15-44 years, by type of assault, race, and sex. United States, 1960 and 1973
Assault by firearm and explosive All persons White males White females Nonwhite males Nonwhite females All other homicide All persons White males White females Nonwhite males Nonwhite females
1960
1973
Absolute increase, 1960-1973
Percentage increase, 1960-1973
4.6 3.4 1.3 36.7 9.2
11.6 94 2.4 91.6 16.2
7.0 6.0 1.1 549 7.0
152 176 85 150 76
3.3 2.0 0.6 30.0 8.6
44 3.3 1.5 28.8 8.3
1.1 1.3 09 -1.2 -0.3
33 65 150 -4 -3
* Standardized to the 1960 United States 15- to 44-year-old population
30O-
200-
I
White Moles Nonwhite Males White Females Nonwtiite Ferrates
100-
I960
1965
I97D Year
FIGURE 5 Age-adjusted death rates among persons 15-44 years of age from all causes other than accidents, homicide and suicide, by race and sex: United States, 1960, 1965, and 1968-1973.
for less than 0.1 per cent of deaths overall and, unless they were highly concentrated within one race-sex-cause of death group, their exclusion is of no consequence. With respect to classification of the "violent" causes of death there is some incomparability between the 7th and 8th Revision of the International Classification
of Disease. The latter was adopted in 1968, and includes a category "Injury undetermined whether accidentally or purposely inflicted" (E980-E989); in the 7th Revision such deaths would have been arbitrarily assigned to a specific violent cause. However, this category currently accounts for less than 3 per cent of deaths from violent causes; its omission here tends to diminish slightly the true increase seen in and after 1968. It is conceivable that during this period there has been some trend in the fashion of certification within the violent causes of death. When the cause of death is in doubt, e.g. between homicide and suicide, current certifiers may tend to choose one category or the other more than was done in 1960. Though the magnitude of this kind of change is unknown it is probably not large, certainly not large enough to account for some of the dramatic increases in homicide rates seen since 1960. Denominator. There are several ways in which errors in determining the size of the population affect the results. The undercount in the 1960 and 1970 censuses has been estimated (3), revealing that males and nonwhites tend to be enumerated less well than females and whites. Depending
TRENDS IN VIOLENT DEATHS AMONG YOUNG ADULTS
on the age group and year, up to 3 per cent of the difference in rates between white males and females and up to 9 per cent of the difference between whites and nonwhites can be explained on this basis. Enumeration in the 1970 census was generally somewhat better than in the 1960 census; this would tend to underestimate slightly any increases in rates that occurred between 1960 and 1970. During the early 1940's there was a rise in young adult male mortality, probably caused by selective overseas migration of healthy males serving in the Armed Forces. Is it possible that the removal of a large number of healthy young males to Southeast Asia in the late 1960's and early 1970's, and thus their removal from both numerator and denominator of conventional mortality statistics, was responsible for an apparent mortality increase in the less healthy population that stayed at home? This may account for some of what has been seen, especially the rapid 1960's mortality rise in 15- to 24-year-old nonwhite males with a subsequent decline in 1971-1973 by which time far fewer men were out of the country. But this factor cannot explain the trends in 25- to 44-yearold males nor can it explain the trends in violent deaths, the probability of which would not seem inversely related to fitness for military duty. This is not to say that the Southeast Asian war could not have contributed to the mortality rise in other ways, e.g. by its psychologic effects on the domestic population. Factors inuolued in the changing homicide rates Even prior to the recent increase, young adults in the United States had homicide rates considerably above those observed in Canada, Western Europe, and Japan, even after adjustment for differences in racial composition (4). Among these countries, the current US trend is being paralleled only in Canada (4). Sizeable changes in homicide rates have occurred previously in
421
the United States. There was a steady rise from the first few years of this century until the mid-1930's, followed by a decline and then a plateau, the latter persisting until about 1960 (5). The rates in the 1930's were approximately the same as today's. Though in some cases it may be evident why specific individuals commit a murder, there is but a modest amount of information available to explain trends in homicide rates in the population. During the past 15 years, this country and the people in it have changed in a number of ways that could possibly relate to the current increase. Firearms. The striking change since 1960 in the rate of homicide associated with firearms suggests strongly that the increased availability and use of guns is an important causal factor. There is no disputing the steadily increasing number of guns in possession of Americans. Over two million were either manufactured or imported in 1960; over six million per year were manufactured or imported in the 1970's (6); both numbers far exceed estimates of the elimination of guns from this society. Although the increased availability has been true for all guns, it applies particularly to the handgun (6), the type of firearm most often used in homicide (7). The most usual circumstances in which murder occurs are altercations among friends or relatives (7). It is possible that, even with no change in the frequency of such altercations an increase in the homicide rate could occur merely from more widespread ownership of handguns, weapons of relatively high lethality (7). Excessive use of alcohol. It would appear reasonable that excessive use of alcohol would be related to the occurrence of homicide, and evidence from several studies suggests that this is indeed the case. Both alcohol intoxication and homicide rates are greater on Friday and Saturday nights than during other times of the week (8). The proportion of homicide victims with high blood alcohol levels, as well as
422
NOEL S WEISS
the proportion of murderers who had been drinking prior to the slaying, seems quite high (9), although there are as yet no data for appropriate comparison groups. During the years 1960-1973, the annual per capita alcohol consumption in the United States increased from 7.84 to 10.18 liters, in contrast to an increase of only .11 liters from 1950-1960 (10). Data on trends in the frequency of intoxication, the measure of alcohol consumption which is probably more pertinent here, are not available. Drug abuse and drug addiction. Of the homicide victims in New York City during 1969-1971, approximately 13 per cent were drug addicts (11). This percentage is almost certainly higher than among non-victims, though by an unknown amount. Also unknown is the percentage of addicts among those who commit homicide. Another study, this of amphetamine users who had committed murder, concluded that amphetamine abuse led to both a life style and behavioral changes that would increase the likelihood of violent acts (12). Political instability. Lester (13) has demonstrated a correlation between a measure of political instability in 36 countries, and their respective homicide rates. No correlation was found with suicide rates. Even if the relationship between political instability and homicide rates were a causal one, however, its relevance to the amount and type of instability during re-
cent times in the United States is uncertain. REFERENCES
1. National Center for Health Statistics. Mortality in Persons 15-44 Years of Age, United States, 1960 and 1968 Monthly Vital Statistics Report. Vol 20, No 9 Suppl USPHS, Washington, DC, Dec 8, 1971 2 Federal Highway Administration Highway Statistics. US GPO, Washington, DC, 1960-1974 3. SiegelJS: Estimates of coverage of the population by sex, race, and age in the 1970 census Demography 11 1-23, 1974 4. Homicide—international comparison Stat Bull Metro Life 536-8, Dec 1972 5 Klebba AJ' Homicide trends in the United States, 1900-74. Public Health Rep 90:195-204, 1975 6. United States Bureau of the Census' Statistical Abstract of the United States: 1974 (95th Edition). Washington, DC 7. Newton GD, Zimring FE- Firearms and Violence in American Life. A Staff Report to the National Commission on the Causes and Prevention of Violence. Washington, DC, US GPO, 1969 8 Wolfgang ME Patterns in Criminal Homicide University of Pennsylvania Press, Philadelphia, 1958 9 Goodwin DW. Alcohol in suicide and homicide. Q J Stud Alcohol 34-144-156, 1973 10. Efron V, Keller M, Gunoh C- Statistics on consumption of alcohol and on alcoholism. Rutgers Center of Alcohol Studies, New Brunswick, NJ, 1974 11. Baden MM: Homicide, suicide, and associated death among narcotic addicts Hum Pathol 3:91-95, 1972 12 Ellinwood EH Assault and homicide associated with amphetamine abuse Am J Psychiatr 127.1170-1175, 1971 13. Lester D: National homicide and suicide rates as a function of political stability. Psychol Rep 33 298, 1973
Copynght © 1976 by The Johns Hopkins University School of Hygiene and Public Health
Vol 103, No 4 Printed in U SA.
RECENT TRENDS IN VIOLENT DEATHS AMONG YOUNG ADULTS IN THE UNITED STATES NOEL S. WEISS Weiss, N. S. (Department of Epidemiology and International Health. School of Public Health and Community Medicine, U. of Washington SC-36. Seattle, WA 98195). Recent trends in violent deaths among young adults in the United States. AmJ Epidemiol 103:416-422.1976. Those Americans who feel that theirs has become an increasingly violent society have support for that belief in recent mortality statistics. Since 1960, death rates in the United States among young adults from motor vehicle accidents, homicide, and suicide have increased dramatically. As of 1973, homicide and suicide rates have shown no indication of leveling off. Death rates from nonviolent causes among young adults, however, are declining, particularly among nonwhite females. accidents, traffic; homicide; mortality; suicide
Among 15- to 34-year-old white males, the rates ceased to increase about 1969, after which they stabilized at the new high levels. Among white males 35-44 years of age the increases following 1960 tended to be small, and by 1973 there was some reduction toward the rates of earlier years. The pattern for white females was similar to that for white males, except that the mortality rise after 1960 was largely confined to the 15- to 24-year group. Death rates for nonwhite males continued their steep climb through 1969, after which there has been a steady decline. Despite this encouraging trend of the last several years, for each age group the death rate was still higher in 1973 than in 1960. For nonwhite females ages 15-24 mortality rates show no definite trend since 1960. For 25- to 44year-olds, however, a steady reduction during the entire interval has taken place, so RESULTS that mortality levels in 1973 were 75-80 per Table 1 presents death rates by race, sex, cent those of 1960. Violent deaths, i.e., those from acciand 5-year age groups from 1960 to 1973. dents, homicide and suicide, account for Received for publication October 6, 1975, and in over 40 per cent of deaths in the 15- to final form November 4, 1975 44-year age group. Substantial increases in Department of Epidemiology and International violent deaths have been shown to repreHealth, School of Public Health and Community Medicine, University of Washington SC-36, Seattle, sent an important factor in the overall WA 98195. mortality rise among young adults between INTRODUCTION
From the initiation of vital statistics records in the United States until about 1960, mortality among young adults (15-44 years of age) had consistently declined. From 1960 to 1968, however, death rates for this age group leveled off and, for males, actually began to rise (1). Increased motor vehicle accident, homicide and suicide rates were an important factor in every color-sex group, although mortality from nonviolent causes among nonwhite males also rose sharply. The present analysis was undertaken to determine what further changes in mortality have occurred in the 5 years between 1968 and 1973. The sources of the data are published and unpublished rates assembled by the National Center for Health Statistics.
416
417
TRENDS IN VIOLENT DEATHS AMONG YOUNG ADULTS TABLE 1
Death rates per 100,000 population among persons ages 15-44 years, by race, sex, and age United States, 1960, 1965, and 1968-1973 Age l l A C c , SCX
White males 1960 1965 1968 1969 1970 1971 1972' 1973 White females 1960 1965 1968 1969 1970 1971 1972* 1973 Nonwhite males 1960 1965 1968 1969 1970 1971 1972* 1973 Nonwhite females 1960 1965 1968 1969 1970 1971 1972* 1973
16-19
20-24
26-29
30-34
35-39
40-44
125.2 130.8 146.8 153.7 147 1 148.1 151.4 156.6
166.9 1719 196.6 202.3 199.0 188.5 192.7 198.6
152.1 157 0 167.1 172 7 169.2 168 1 167 6 173.3
173.2 179 3 182.7 184.4 185.4 181.9 178.7 182.7
240 2 257.4 264 5 265.1 260 4 257.0 246 6 252.1
416.9 411.4 420.7 424.5 420.0 407.0 399.6 394.3
50.2 50.1 57.4 58.7 57.8 57 6 58.3 57 9
60.4 63.3 645 65.7 657 63.1 643 62.4
71.5 70.0 70.9 71.1 73 1 73.3 696 69.1
97.1 101.7 96.3 987 972 94.4 95 0 91.5
147 5 151 3 152 3 152.8 150.9 142 5 142 6 140 7
237.9 2353 2399 240.8 232.0 233.4 228.9 221.8
165 8 168.9 214 6 235 8 224 0 218 4 208.6 190.2
274 8 2886 3659 394.3 415.5 434.3 416 8 384.6
343.0 392.9 454.9 455.2 456 6 493.6 472.2 474 7
428.6 479 6 593.9 589.5 5588 541.6 562 4 526.1
599.2 6865 772 1 788 1 723 7 740.1 747 0 705.4
876 5 936.3 1067 4 1080 9 1024 3 965.6 9904 925.6
804 78.8 81 3 94.7 847 90.0 79.0 79 6
135 7 125.7 138 4 135 8 138 1 137 5 133 1 132.4
210.2 194 0 200.5 192.0 185.2 180.8 176.0 161.6
307.8 3016 3034 293.9 250.0 258.8 244 8 230.9
448 1 442.8 4484 435.0 395 7 3987 3617 3547
6608 636.8 642 3 613 0 5863 562.6 5505 525 7
* Rates based on 50% sample of deaths.
1960 and 1968 (1). Thus, these causes have been singled out here for a closer look. Figures 1-4 present race and sex-specific mortality rates among persons 15-44 years of age for motor vehicle accidents, other accidents, homicide, and suicide, respectively. Because of the pronounced change in the age structure of the 15- to 44-yearold population between 1960 and 1973, the rates have been age-adjusted. The direct method was used; the total 15- to 44-year-
old 1960 population was arbitrarily chosen as the standard. Motor vehicle accident mortality increased, depending on the race and sex group, by 25 to 50 per cent during the 1960's (figure 1). Rates rose substantially both for pedestrian and non-pedestrian accidents. Beginning in 1970, however, motor vehicle accident mortality among males dipped and that among females leveled off. The high male/female mortal-
418
NOEL S WEISS IIIL
70-
130-
——
1.
M_l
-
^
.
Hfwiwhitp Urdfn;
/
White Femoles
60-
\
120/
50-
110i i
White Males Nonwhrte Males While Females Nonwhrte Females
30-
100-
/ /
o
V
/
\ k
Ax /
4
i
i
i
I i
90QJ
i
S 20-1
\
i i
t 1 1
I i
s 80-
s 70» •
• •
I960
1970
1965
20-
...
- • '*
•»••
Year
FIGURE 1 Age-adjusted death rates from motor vehicle accidents among persons 15-44 years of age, by race and sex United States, 1960, 1965, and 1968-1973
10-
I960
1965
1970
Year
FIGURE 3 Age-adjusted homicide rates among persons 15-44 years of age, by race and sex- United States, 1960, 1965 and 1968-1973. 60-
•
§50-
'—•« white males
•--—--•
Nonwfute motes
• — —••
White females
•
Nonwhite females
per
•
§30§20-
10-
I960
1965
1970 Year
FIGURE 2 Age-adjusted death rates from accidents (other than motor vehicle) among persons 15-44 years of age, by race and sex United States, 1960, 1965, and 1968-1973.
ity ratio was present at all years. The annual number of miles traveled by motor vehicles in the United States increased by 50 per cent between 1960 and 1970 and, in contrast to the motor vehicle accident death rate, continued to rise steadily through 1973 (2). What did level off in the early 1970's, however, was the average vehicle speed (2). Death rates from other types of accidents remained relatively stationary for each of the race and sex groups during the 1960-1973 interval (figure 2); rates for nonwhite males rose somewhat during the 1960's, but have fallen again since 1970. Figure 3 depicts the alarming situation with respect to homicide, as rates in all groups increased during the 1960's and continued to do so in the early 1970's. The increase was greatest for males and, though
TRENDS IN VIOLENT DEATHS AMONG YOUNG ADULTS
20-
White Molts Nonwtote Moles White Females Nonwhite Femoles
IO J
s I960
1965
1970 Year
FIGURE 4. Age-adjusted suicide rates among persons 15-44 years of age, by race and sex- United States, 1960, 1966, and 1968-1973.
the relative change was approximately the same in whites and nonwhites, because nonwhite males had by far the highest homicide rate initially they experienced the greatest absolute increase. Between 1960 and 1973, the annual difference in the homicide rate between nonwhite and white males rose from 61.3 per 100,000 to 107.7 per 100,000. In 1973, homicide rates for nonwhite males were about 10 times the rate for white males and more than 30 times the rate for white females. Each of the 5-year age subgroups in the 15-44 year range of the nonwhite male population shared in the rapid increase. Homicide resulting from use of firearms and explosives accounted for the large majority of the rising rates during this period (table 2), and among nonwhites homicide not involving firearms actually declined slightly. Suicide rates have also been increasing among young adults (figure 4); between 1960 and 1973, there was an increase of approximately 25 per cent for each of the four race-sex groups. The two most common means of committing suicide, by poisoning and the use of firearms, showed the largest relative increases during the interval. In every year suicide among whites and males was more common than among nonwhites and females.
419
Perhaps the only encouraging aspect of these statistics is found in figure 5, which presents the trends in mortality for causes other than accidents, homicide or suicide. These rates are currently declining among all groups in the 15- to 44-year age range. White females have the lowest rate of all, one that has slowly but persistently fallen since 1960. During the 1960's white male mortality from nonviolent causes was stable, but a small decline has occurred since 1970. The rate for nonwhite females has fallen more dramatically than the others; the fall is particularly precipitous after 1968. Their mortality from nonviolent causes in 1973 was 28 per cent lower than in 1960. Even the rate for nonwhite males, which in the 1960's rose for the first time, has declined steadily in the early 1970's. DISCUSSION
Limitations of the data There are a number of known limitations and inaccuracies in the rates presented here. The magnitude of each can be fairly well approximated, and none is great enough to materially affect the interpretation of the results. They are detailed as follows. Numerator. Military or civilian deaths which occurred outside the US were excluded from the rates for all of the years. The only deaths resulting from the war in Southeast Asia included here were in persons who survived their injuries long enough so that death occurred in the US. These deaths have to a very small extent inflated the "all-cause" rates for men in the late 1960's and early 1970's. In 1970, for instance, there were 32 such deaths (coded to "Injury resulting from operations of war" (E990-E999)) among men in this age group, corresponding to but 0.03 per cent of the total. Deaths occurring among nonresidents of the US were included in the computation of the rates through 1969, after which they were excluded. However, these accounted
420
NOEL S WEISS TABLE 2
Homicide rates* per 100,000 population among persons ages 15-44 years, by type of assault, race, and sex. United States, 1960 and 1973
Assault by firearm and explosive All persons White males White females Nonwhite males Nonwhite females All other homicide All persons White males White females Nonwhite males Nonwhite females
1960
1973
Absolute increase, 1960-1973
Percentage increase, 1960-1973
4.6 3.4 1.3 36.7 9.2
11.6 94 2.4 91.6 16.2
7.0 6.0 1.1 549 7.0
152 176 85 150 76
3.3 2.0 0.6 30.0 8.6
44 3.3 1.5 28.8 8.3
1.1 1.3 09 -1.2 -0.3
33 65 150 -4 -3
* Standardized to the 1960 United States 15- to 44-year-old population
30O-
200-
I
White Moles Nonwhite Males White Females Nonwtiite Ferrates
100-
I960
1965
I97D Year
FIGURE 5 Age-adjusted death rates among persons 15-44 years of age from all causes other than accidents, homicide and suicide, by race and sex: United States, 1960, 1965, and 1968-1973.
for less than 0.1 per cent of deaths overall and, unless they were highly concentrated within one race-sex-cause of death group, their exclusion is of no consequence. With respect to classification of the "violent" causes of death there is some incomparability between the 7th and 8th Revision of the International Classification
of Disease. The latter was adopted in 1968, and includes a category "Injury undetermined whether accidentally or purposely inflicted" (E980-E989); in the 7th Revision such deaths would have been arbitrarily assigned to a specific violent cause. However, this category currently accounts for less than 3 per cent of deaths from violent causes; its omission here tends to diminish slightly the true increase seen in and after 1968. It is conceivable that during this period there has been some trend in the fashion of certification within the violent causes of death. When the cause of death is in doubt, e.g. between homicide and suicide, current certifiers may tend to choose one category or the other more than was done in 1960. Though the magnitude of this kind of change is unknown it is probably not large, certainly not large enough to account for some of the dramatic increases in homicide rates seen since 1960. Denominator. There are several ways in which errors in determining the size of the population affect the results. The undercount in the 1960 and 1970 censuses has been estimated (3), revealing that males and nonwhites tend to be enumerated less well than females and whites. Depending
TRENDS IN VIOLENT DEATHS AMONG YOUNG ADULTS
on the age group and year, up to 3 per cent of the difference in rates between white males and females and up to 9 per cent of the difference between whites and nonwhites can be explained on this basis. Enumeration in the 1970 census was generally somewhat better than in the 1960 census; this would tend to underestimate slightly any increases in rates that occurred between 1960 and 1970. During the early 1940's there was a rise in young adult male mortality, probably caused by selective overseas migration of healthy males serving in the Armed Forces. Is it possible that the removal of a large number of healthy young males to Southeast Asia in the late 1960's and early 1970's, and thus their removal from both numerator and denominator of conventional mortality statistics, was responsible for an apparent mortality increase in the less healthy population that stayed at home? This may account for some of what has been seen, especially the rapid 1960's mortality rise in 15- to 24-year-old nonwhite males with a subsequent decline in 1971-1973 by which time far fewer men were out of the country. But this factor cannot explain the trends in 25- to 44-yearold males nor can it explain the trends in violent deaths, the probability of which would not seem inversely related to fitness for military duty. This is not to say that the Southeast Asian war could not have contributed to the mortality rise in other ways, e.g. by its psychologic effects on the domestic population. Factors inuolued in the changing homicide rates Even prior to the recent increase, young adults in the United States had homicide rates considerably above those observed in Canada, Western Europe, and Japan, even after adjustment for differences in racial composition (4). Among these countries, the current US trend is being paralleled only in Canada (4). Sizeable changes in homicide rates have occurred previously in
421
the United States. There was a steady rise from the first few years of this century until the mid-1930's, followed by a decline and then a plateau, the latter persisting until about 1960 (5). The rates in the 1930's were approximately the same as today's. Though in some cases it may be evident why specific individuals commit a murder, there is but a modest amount of information available to explain trends in homicide rates in the population. During the past 15 years, this country and the people in it have changed in a number of ways that could possibly relate to the current increase. Firearms. The striking change since 1960 in the rate of homicide associated with firearms suggests strongly that the increased availability and use of guns is an important causal factor. There is no disputing the steadily increasing number of guns in possession of Americans. Over two million were either manufactured or imported in 1960; over six million per year were manufactured or imported in the 1970's (6); both numbers far exceed estimates of the elimination of guns from this society. Although the increased availability has been true for all guns, it applies particularly to the handgun (6), the type of firearm most often used in homicide (7). The most usual circumstances in which murder occurs are altercations among friends or relatives (7). It is possible that, even with no change in the frequency of such altercations an increase in the homicide rate could occur merely from more widespread ownership of handguns, weapons of relatively high lethality (7). Excessive use of alcohol. It would appear reasonable that excessive use of alcohol would be related to the occurrence of homicide, and evidence from several studies suggests that this is indeed the case. Both alcohol intoxication and homicide rates are greater on Friday and Saturday nights than during other times of the week (8). The proportion of homicide victims with high blood alcohol levels, as well as
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NOEL S WEISS
the proportion of murderers who had been drinking prior to the slaying, seems quite high (9), although there are as yet no data for appropriate comparison groups. During the years 1960-1973, the annual per capita alcohol consumption in the United States increased from 7.84 to 10.18 liters, in contrast to an increase of only .11 liters from 1950-1960 (10). Data on trends in the frequency of intoxication, the measure of alcohol consumption which is probably more pertinent here, are not available. Drug abuse and drug addiction. Of the homicide victims in New York City during 1969-1971, approximately 13 per cent were drug addicts (11). This percentage is almost certainly higher than among non-victims, though by an unknown amount. Also unknown is the percentage of addicts among those who commit homicide. Another study, this of amphetamine users who had committed murder, concluded that amphetamine abuse led to both a life style and behavioral changes that would increase the likelihood of violent acts (12). Political instability. Lester (13) has demonstrated a correlation between a measure of political instability in 36 countries, and their respective homicide rates. No correlation was found with suicide rates. Even if the relationship between political instability and homicide rates were a causal one, however, its relevance to the amount and type of instability during re-
cent times in the United States is uncertain. REFERENCES
1. National Center for Health Statistics. Mortality in Persons 15-44 Years of Age, United States, 1960 and 1968 Monthly Vital Statistics Report. Vol 20, No 9 Suppl USPHS, Washington, DC, Dec 8, 1971 2 Federal Highway Administration Highway Statistics. US GPO, Washington, DC, 1960-1974 3. SiegelJS: Estimates of coverage of the population by sex, race, and age in the 1970 census Demography 11 1-23, 1974 4. Homicide—international comparison Stat Bull Metro Life 536-8, Dec 1972 5 Klebba AJ' Homicide trends in the United States, 1900-74. Public Health Rep 90:195-204, 1975 6. United States Bureau of the Census' Statistical Abstract of the United States: 1974 (95th Edition). Washington, DC 7. Newton GD, Zimring FE- Firearms and Violence in American Life. A Staff Report to the National Commission on the Causes and Prevention of Violence. Washington, DC, US GPO, 1969 8 Wolfgang ME Patterns in Criminal Homicide University of Pennsylvania Press, Philadelphia, 1958 9 Goodwin DW. Alcohol in suicide and homicide. Q J Stud Alcohol 34-144-156, 1973 10. Efron V, Keller M, Gunoh C- Statistics on consumption of alcohol and on alcoholism. Rutgers Center of Alcohol Studies, New Brunswick, NJ, 1974 11. Baden MM: Homicide, suicide, and associated death among narcotic addicts Hum Pathol 3:91-95, 1972 12 Ellinwood EH Assault and homicide associated with amphetamine abuse Am J Psychiatr 127.1170-1175, 1971 13. Lester D: National homicide and suicide rates as a function of political stability. Psychol Rep 33 298, 1973
