Читать книгу Lifespan Development - Tara L. Kuther - Страница 316

Begun in 1956, the New York Longitudinal Study followed 133 infants into adulthood. Early in life, the infants in the study demonstrated differences several characteristics that are thought to capture the essence of temperament (Thomas & Chess, 1977; Thomas, Chess, & Birch, 1970). For example, infants differ in activity level; some wriggle, kick their legs, wave their arms, and move around a great deal, whereas others tend to be more still and stay in one place. Some infants have predictable patterns of eating and sleeping, and others are not predictable. Infants also differ in the intensity of their reactions, their tendency to approach or withdraw from new things, and their distractibility. Some aspects of infant temperament, particularly activity level, irritability, attention, and sociability or approach-withdrawal, show stability for months and years at a time and in some cases even into adulthood (Lemery-Chalfant, Kao, Swann, & Goldsmith, 2013; Papageorgiou et al., 2014). Thomas and Chess classified infant temperament into three profiles (Thomas & Chess, 1977; Thomas et al., 1970).

 Easy temperament: Easy babies are often in a positive mood, even-tempered, open, adaptable, regular, and predictable in biological functioning. They establish regular feeding and sleeping schedules easily.

 Difficult temperament: Difficult babies are active, irritable, and irregular in biological rhythms. They are slow to adapt to changes in routine or new situations, react vigorously to change, and have trouble adjusting to new routines.

 Slow-to-warm-up temperament: Just as it sounds, slow-to-warm-up babies tend to be inactive, moody, and slow to adapt to new situations and people. They react to new situations with mild irritability but adjust more quickly than do infants with difficult temperaments.

Although it may seem as if all babies could be easily classified, about one third of the infants in the New York Longitudinal Study did not fit squarely into any of the three categories but displayed a mix of characteristics, such as eating and sleeping regularly but being slow to warm up to new situations (Thomas & Chess, 1977; Thomas et al., 1970).

Another influential model of temperament, by Mary Rothbart, includes three dimensions (Rothbart, 2011; Rothbart & Bates, 2007):

 Extraversion/surgency: the tendency toward positive emotions. Infants who are high in extraversion/surgency approach experiences with confidence, energy, and positivity, as indicated by smiles, laughter, and approach-oriented behaviors.

 Negative affectivity: the tendency toward negative emotions, such as sadness, fear, distress, and irritability.

 Effortful control: the degree to which one can focus attention, shift attention, and inhibit responses in order to manage arousal. Infants who are high in effortful control are able to regulate their arousal and soothe themselves.

From this perspective, temperament reflects how easily we become emotionally aroused or our reactivity to stimuli, as well as how well we are able to control our emotional arousal (Rothbart, 2011). Some infants and children are better able to distract themselves, focus their attention, and inhibit impulses than others. The ability to self-regulate and manage emotions and impulses is associated with positive long-term adjustment, including academic achievement, social competence, and resistance to stress, in both Chinese and North American samples (Chen & Schmidt, 2015).

Infant temperament tends to be stable over the first year of life but less so than childhood temperament, which can show stability over years, even into adulthood (Bornstein et al., 2015). In infancy, temperament is especially open to environmental influences, such as interactions with others (Gartstein, Putnam, Aron, & Rothbart, 2016). Young infants’ temperament can change with experience, neural development, and sensitive caregiving (e.g., helping babies regulate their negative emotions) (Jonas et al., 2015; Thompson et al., 2013). As infants gain experience and learn how to regulate their states and emotions, those who are cranky and difficult may become less so. By the second year of life, styles of responding to situations and people are better established, and temperament becomes more stable. Temperament at age 3 remains stable, predicting temperament at age 6 and personality traits at age 26 (Dyson et al., 2015).