PsychologicalReports, 1990, 67, 192-194. O Psychological Reports 1990
NIGHT WAKING AND TEMPERAMENT IN EARLY CHILDHOOD ' CHARLES E. SCHAEFER Fairleigh Dickinson University Summary.-A study df 100 young children referred to a Crying Baby Clinic for repeated waking at night yielded a less than expected incidence of "easy" ternperaments and a greater number of "difficult" temperaments in the children.
Sleeping difficulties are the most common behavior problems exhibited by infants. Estimates of night waking are 30% in infants 6 to 14 mo. of age and slightly less for infants ages 15 to 27 mo. (Moore & Ucko, 1957). Despite the frequent occurrence of night waking in infants, there is little conclusive evidence as to the cause. One possible determinant is the infant's temperament. In the New York Longitudinal Study (NYLS), Thomas and Chess (1977) investigated individual differences in infants' behavior and designated the stylistic differences as temperamental characteristics. They identified the following nine categories of temperament: activity, rhythmicity, approach/ withdrawal, adaptability, intensity, mood, distractibility, persistence, and threshold. They also described three broad patterns of temperamental characteristics: "difficult," "easy," and "slow-to-warm-up." Thomas and Chess view temperament as composed of organismic characteristics which are biologically determined but which are constantly interacting with the environment and therefore not immutable. In their research, children with "difficult" temperaments at age three had more concurrent and later behavioral problems. Similarly, a low but significant relationship has been reported between "difficult" temperaments and fussiness in infants (Bates, 1979). The purpose of the present study was to investigate the possibility of a relationship between temperament and night waking in young children.
METHOD The subjects were 100 children treated during 1988-89 by the author at Fairleigh Dickinson University's Crying Baby Clinic. The children were all Caucasians from middle- to upper-middle-class backgrounds, and ranged in age from 6 rno. to 3 yr. (mean age of 18 mo.). Of the 54 boys and 46 girls in the sample, 78 were first-born children. All of the children met Moore and Ucko's (1957) definition of night waking: child awakened and cried one 'Address correspondence to C. E. Schaefer, Ph.D., Director of Training, Division of Psychological Services, Fairleigh Dickinson University, 139 Temple Avenue, Hackensack, NJ 07601.
NIGHT WAKING AND TEMPERAMENT
193
or more times between midnight and 5 a.m. at least four out of seven nights for at least four consecutive weeks. Temperament was measured by a widely used questionnaire developed by Carey and his colleagues on the basis of the New York Longitudinal Study's conceptualization of temperament. The Revised Infant Temperament Questionnaire (Carey & McDevitt, 1978) was completed during the intake procedure by parents of children up to one year of age, while the Toddler Temperament Scale (Fullard, McDevitt, & Carey, 1984) was filled out by parents of children ages 1 to 3 yr. None of the items on the two questionnaires addressed the question of infants' night walung. The children were divided into four groups in accord with their ratings on five temperament characteristics. Group one consisted of "easy" babies who were described by their mothers as regular, adaptable, approaching, mild, and positive in mood. Group two were "difficult" babies who were rated as irregular, low in adaptability and initial approach, intense, and negative in mood. Group three was composed of "mixed" cases which fell between "easy" and "difficult" categories. Group four contained "slowto-warm-up" children who exhibited negative responses and slow adaptability to new stimuli and their positive and negative reactions were characterized by rnild intensity. Previous research had not shown the temperament styles of children to be related either to the parents' methods of child-rearing or to the parents' own personality styles.
The number of cases falling into each of the four temperament styles is presented in Table 1. Also, the number of cases expected in each category based on normative data of Thomas and Chess (1977) is included in the TABLE
1
FREQUENCY DISTRIBUTION OF TF~PERAMENTAL S~LES Temperament 6-12 Easy
Difficult
Mixed Slow-to-warm-UD
1 5 13 3
Age, mo. 13-23 14 8 26 5
Total
Expected
22 19 48 11
40 10 35 15
24-36
7 6 9 3
table. A chi squared analysis was performed comparing the actual versus expected number of cases within each of the four styles. Chi squared was significant (X; = 22.1, p < .001). Inspection of Table 1 indicates that there were fewer children of "easy" temperament than expected while the numbers of "difficult" and "mixed" temperament cases were greater than expected.
194
C. E. SCHAEFER
Drscuss~o~ The results indicate that night waking is found among children with widely differing temperaments. However, young children with "easy" temperaments were significantly under-represented among the night wakers in the present study. Conversely, a greater than expected number of children with "difficult7' temperaments was apparent. The present findings are consistent with Weissbluth's (1981) observation that children with difficult temperaments sleep about two hours less each night and one hour less each day than children with easy temperaments. Consideration of temperament discourages the one-sided emphasis on family dynamics or parents' personality as causative factors in childhood disorders. Such an emphasis tends to assign blame and enhance or create guilt over parenting failures. The identification of "difficult" characteristics in a child can lessen the guilt, anger, and apprehension of parents, especially first-time parents with children who wake repeatedly at night. REFERENCES BATES,J. E., FREELANO, C. A., & LOUNSBURG, M. L. (1979) Measurement of infant difficulties. Child Development, 50, 794-803. CAREY, W.B.,& MCDEVI~T,S. C. (1978) Revision of the Infant Temperament Questionnaire. Pediatrics, 61, 735-739. FULLARO, W.,MCDEVITT,S. C., & CAREY,W.B. (1984) Assessing temperament in one- to three-year-old children. Journal of Pediatric Psychology, 9, 205-217. MOORE,T., & UCKO,L. E. (1957) Night waking in early infancy. Archives Diseases of Childhood, 32, 333. THOMAS, A , , & CHESS,S. (1977) Temperament and development. New York: Brunner/Mazel. WEISSBLUTH, M. (1981) Sleep duration and infant temperament. Pediatrics, 99, 817-819.
Accepted June 18, 1990.
NIGHT WAKING AND TEMPERAMENT IN EARLY CHILDHOOD ' CHARLES E. SCHAEFER Fairleigh Dickinson University Summary.-A study df 100 young children referred to a Crying Baby Clinic for repeated waking at night yielded a less than expected incidence of "easy" ternperaments and a greater number of "difficult" temperaments in the children.
Sleeping difficulties are the most common behavior problems exhibited by infants. Estimates of night waking are 30% in infants 6 to 14 mo. of age and slightly less for infants ages 15 to 27 mo. (Moore & Ucko, 1957). Despite the frequent occurrence of night waking in infants, there is little conclusive evidence as to the cause. One possible determinant is the infant's temperament. In the New York Longitudinal Study (NYLS), Thomas and Chess (1977) investigated individual differences in infants' behavior and designated the stylistic differences as temperamental characteristics. They identified the following nine categories of temperament: activity, rhythmicity, approach/ withdrawal, adaptability, intensity, mood, distractibility, persistence, and threshold. They also described three broad patterns of temperamental characteristics: "difficult," "easy," and "slow-to-warm-up." Thomas and Chess view temperament as composed of organismic characteristics which are biologically determined but which are constantly interacting with the environment and therefore not immutable. In their research, children with "difficult" temperaments at age three had more concurrent and later behavioral problems. Similarly, a low but significant relationship has been reported between "difficult" temperaments and fussiness in infants (Bates, 1979). The purpose of the present study was to investigate the possibility of a relationship between temperament and night waking in young children.
METHOD The subjects were 100 children treated during 1988-89 by the author at Fairleigh Dickinson University's Crying Baby Clinic. The children were all Caucasians from middle- to upper-middle-class backgrounds, and ranged in age from 6 rno. to 3 yr. (mean age of 18 mo.). Of the 54 boys and 46 girls in the sample, 78 were first-born children. All of the children met Moore and Ucko's (1957) definition of night waking: child awakened and cried one 'Address correspondence to C. E. Schaefer, Ph.D., Director of Training, Division of Psychological Services, Fairleigh Dickinson University, 139 Temple Avenue, Hackensack, NJ 07601.
NIGHT WAKING AND TEMPERAMENT
193
or more times between midnight and 5 a.m. at least four out of seven nights for at least four consecutive weeks. Temperament was measured by a widely used questionnaire developed by Carey and his colleagues on the basis of the New York Longitudinal Study's conceptualization of temperament. The Revised Infant Temperament Questionnaire (Carey & McDevitt, 1978) was completed during the intake procedure by parents of children up to one year of age, while the Toddler Temperament Scale (Fullard, McDevitt, & Carey, 1984) was filled out by parents of children ages 1 to 3 yr. None of the items on the two questionnaires addressed the question of infants' night walung. The children were divided into four groups in accord with their ratings on five temperament characteristics. Group one consisted of "easy" babies who were described by their mothers as regular, adaptable, approaching, mild, and positive in mood. Group two were "difficult" babies who were rated as irregular, low in adaptability and initial approach, intense, and negative in mood. Group three was composed of "mixed" cases which fell between "easy" and "difficult" categories. Group four contained "slowto-warm-up" children who exhibited negative responses and slow adaptability to new stimuli and their positive and negative reactions were characterized by rnild intensity. Previous research had not shown the temperament styles of children to be related either to the parents' methods of child-rearing or to the parents' own personality styles.
The number of cases falling into each of the four temperament styles is presented in Table 1. Also, the number of cases expected in each category based on normative data of Thomas and Chess (1977) is included in the TABLE
1
FREQUENCY DISTRIBUTION OF TF~PERAMENTAL S~LES Temperament 6-12 Easy
Difficult
Mixed Slow-to-warm-UD
1 5 13 3
Age, mo. 13-23 14 8 26 5
Total
Expected
22 19 48 11
40 10 35 15
24-36
7 6 9 3
table. A chi squared analysis was performed comparing the actual versus expected number of cases within each of the four styles. Chi squared was significant (X; = 22.1, p < .001). Inspection of Table 1 indicates that there were fewer children of "easy" temperament than expected while the numbers of "difficult" and "mixed" temperament cases were greater than expected.
194
C. E. SCHAEFER
Drscuss~o~ The results indicate that night waking is found among children with widely differing temperaments. However, young children with "easy" temperaments were significantly under-represented among the night wakers in the present study. Conversely, a greater than expected number of children with "difficult7' temperaments was apparent. The present findings are consistent with Weissbluth's (1981) observation that children with difficult temperaments sleep about two hours less each night and one hour less each day than children with easy temperaments. Consideration of temperament discourages the one-sided emphasis on family dynamics or parents' personality as causative factors in childhood disorders. Such an emphasis tends to assign blame and enhance or create guilt over parenting failures. The identification of "difficult" characteristics in a child can lessen the guilt, anger, and apprehension of parents, especially first-time parents with children who wake repeatedly at night. REFERENCES BATES,J. E., FREELANO, C. A., & LOUNSBURG, M. L. (1979) Measurement of infant difficulties. Child Development, 50, 794-803. CAREY, W.B.,& MCDEVI~T,S. C. (1978) Revision of the Infant Temperament Questionnaire. Pediatrics, 61, 735-739. FULLARO, W.,MCDEVITT,S. C., & CAREY,W.B. (1984) Assessing temperament in one- to three-year-old children. Journal of Pediatric Psychology, 9, 205-217. MOORE,T., & UCKO,L. E. (1957) Night waking in early infancy. Archives Diseases of Childhood, 32, 333. THOMAS, A , , & CHESS,S. (1977) Temperament and development. New York: Brunner/Mazel. WEISSBLUTH, M. (1981) Sleep duration and infant temperament. Pediatrics, 99, 817-819.
Accepted June 18, 1990.
