Though facial expressions are argued to be among the most “basic” forms of emotional communication, it would be incorrect to assume that emotional expressions are decoded and comprehended perfectly from birth. A body of research has accumulated to characterize the acquisition of different expression recognition abilities across development. This section will briefly address the development of each of these stages of facial emotion recognition, and we refer readers to more comprehensive accounts of these issues that have been published elsewhere (Herba & Phillips, 2004
; Nelson, 1987
; Walker-Andrews, 1997
Evidence suggests that around three months of age, infants’ ability to focus sight begins to approach maturity (Banks, 1980
). Prior to this developmental landmark, infants likely rely on high-contrast features that may permit the detection of face-like shapes (Campos & Sternberg, 1981
) but may not support the discrimination of distinct emotional expressions (for a review, see Nelson, 1987
). Slightly later, infants show reliable changes in their behavior in response to viewing different emotional expressions. A creative experiment by Montague and colleagues (Montague & Walker-Andrews, 2001
) measured looking time and imitation in infants during a “peek-a-boo” game. Each time the experimenter uncovered her face, she configured it into a happy, sad, fearful, or angry expression. Reliable differences in looking time as a function of expression provided evidence that infants as young as four months of age can discriminate between expressions, consistent with other reports (Field, Woodson, Greenberg, & Cohen, 1982
; Haviland & Lelwica, 1987
). Slightly later, seven month old infants show longer looking times in response to fearful expressions (de Haan, Belsky, Reid, Volein, & Johnson, 2004
), and around 10 months, infants are able to reliably differentiate between expressions within a canonical valence category (e.g., differentiation between expressions of happy and pleasant surprise within the class of “positive expressions”) (Ludemann, 1991
). Thus, the available evidence suggests that a gradual refinement occurs in detection of and discrimination among facial expressions in the first year of life and beyond. However, under more difficult task conditions such as rapid presentation (Tottenham, Leon, & Casey, 2006
) and presentation of subtle morphed expressions (Thomas, De Bellis, Graham, & LaBar, 2007
), even adolescents show performance deficits relative to adults, suggesting that more fine-grained aspects of facial expression recognition continue to develop until adulthood.
Although expression detection and discrimination represent important developmental milestones, it remains unclear whether these effects are mediated by perceptual discrimination or a higher-order understanding of what different expressions mean. This issue is difficult to untangle, given the inherent problems in measuring higher order understanding using the instruments available to test the youngest infants, who are preverbal and limited in their capacity for intentional motor activity (McClure, 2000
). The available evidence suggests that slightly later in development, infants not only understand expression meanings, but they also use this understanding to make behavioral choices. In a visual cliff paradigm, one year olds were much less likely to crawl over an apparent drop-off if their mothers posed fearful faces than if they posed happy faces (Sorce, Emde, Campos, & Klinnert, 1985
). Similar social referencing effects have been observed in other contexts around this age as well (Feinman & Lewis, 1983
; Gunnar & Stone, 1984
; Hornik & Gunnar, 1988
). So, around one year, there is clear evidence that infants look to the facial expressions of surrounding individuals, particularly parents, to guide their own behavior.
While expression differentiation abilities appear to be fairly mature by at least one year of age, the ability to accurately label and match different depictions of the same emotional expression slowly emerges throughout childhood (for a more comprehensive review, see Gross & Ballif, 1991
). Performance on matching emotional expressions shows steady improvement over development, with prominent improvements in accuracy observed between 9 and 10 years, and then again between 13 and 14 years, after which performance approximates that of adults (Kolb, Wilson, & Taylor, 1992
). Further, the developmental timecourse of this ability is not uniform across emotional expressions. While preschoolers can consistently label certain emotions correctly, such as happy, as happy or joyful (Camras & Allison, 1985
), children remain susceptible to errors in labeling other emotions, such as sad, surprised, disgusted, and afraid for years to come (Herba, Landau, Russell, Ecker, & Phillips, 2006
One could argue that the capacity to label or match expressions is irrelevant to social behavior unless it facilitates the ability to infer the appropriate emotional response to a given situation. This has also been examined across development, and the results parallel those from studies of emotion matching and labeling. Kolb and colleagues (1992)
presented 6 to 15 year old children with a series of line-drawn cartoons. In each depicted scene, the facial expression of one character was left blank in the image (for example, a boy with a blank face holds a cat just hit by a car). The task was to choose the most appropriate facial expression to represent the emotion the blank-faced individual was likely to be feeling (in the example, the correct answer was sadness). As expected, performance on this task steadily improved with age, but not uniformly across expression. Participants were fastest to achieve matching accuracy for angry and happy scenarios, with adult-level performance evident at the youngest age tested (6 years). In contrast, sad, fearful, disgusted, and surprised scenario-expression matching improved steadily with increasing age, only approaching adult performance during adolescence.
Finally, it should be noted that across all age groups, females appear to possess a subtle advantage in processing emotional expressions relative to males. In a meta-analysis focused on studies of youth, McClure (2000)
observed a small yet reliable enhancement in performance on the tasks described above in females relative to males. This group difference was present across development, but was largest in infancy and early childhood. Taken together with Hall's (1984)
meta-analytic findings of a consistent female advantage for expression processing in adults, these findings suggest that sex differences wax and wane at different points in the lifespan, with a small, but significant, tendency for females to perform better on relevant tasks.
Responses to emotional cues appear to undergo another fundamental shift in late adulthood. Psychological aging research has shown late adulthood to be characterized by an overall improvement of emotional experience. Empirically, it has been demonstrated that older adults experience less negative affect (Carstensen, Pasupathi, Mayr, & Nesslroade, 2000
; Charles, Reynolds, & Gatz, 2001
; Phillips et al., 2006
), show fewer outward displays of emotion (Magai, Cosedine, Krivoshekova, Kudadjic-Gyamfi, & McPherson, 2006
; Phillips, Henry, Hosie, & Milne, 2006
), and show a decreased magnitude of emotional memory enhancement for negative material (Charles, Mather, & Carstensen, 2003
), despite the fact that threat detection processes (Mather & Knight, 2006
) and physiological responses to negative images (Denberg, Buchanan, Tranel, & Adolphs, 2003
) appear to be intact. In addition to less negative affect, older adults seem to also experience a heightened level of positive affect (Carstensen et al., 2000
) and subjective quality of life (Phillips et al., 2006
). This shift in emotional experience has been interpreted within the theoretical framework of socioemotional selectivity theory, developed by Carstensen and colleagues (Carstensen, 1995
; Carstensen, Fung, & Charles, 2003
). This theory posits that in late adulthood, individuals begin to think of their remaining time in life as limited, inducing a shift in focus away from future-oriented stressors and other sources of negative affect, and toward emotionally meaningful sources of positive affect.
Concurrent with shifts toward positive emotional experiences late in life is a change in the ability to recognize different categories of emotional facial expressions. It is plausible, and perhaps expected, that older adults (defined here as over 65 years of age) would show facial expression recognition deficits due to nonspecific decrements in cognitive and perceptual processing (Burke & Mackay, 1997
). However, it is also possible that older adults demonstrate expression- or valence-specific deficits, consistent with changes in affective processing late in life (Calder et al., 2003
). A recent meta-analysis (Ruffman, Henry, Livingstone, & Phillips, 2008
) concluded that older adults show specific deficits in the ability to correctly recognize sad, angry and fearful expressions. This is not consistent with a general performance deficit, as the recognition of surprised, happy and disgusted expressions does not appear to decline with advanced age. Interestingly, the expressions showing a drop in recognition with advancing age are all negative in valence, which may be consistent with older adults’ renewed focus on positive affect. These findings provide further evidence for the dynamic nature facial expression recognition across the lifespan, with additional changes observed very late in life.
In summary, the development of facial expression recognition and comprehension is characterized by a gradual improvement in the ability to differentiate between emotions, to place verbal labels on emotional expressions, and to determine the most appropriate emotional response to a given situation from early childhood to adulthood (Lewis, Lamm, Segalowitz, Stieben, & Zelazo, 2006
). However, the comprehension and identification of different emotions does not necessarily develop uniformly. Children appear quickest to master accurate recognition of happy expressions and slower to identify other expressions such as fear, sadness, anger, and disgust. Accurate discrimination among facial cues of different negative emotions does not reach adult-level performance until the teenage years. Emotional categories of sadness, anger, and fear – among the latest to attain accurate identification - are also those that show the earliest decrement in processing in the late adult years.