Person-Specific Non-shared Environmental Influences in Intra-individual Variability: A Preliminary Case of Daily School Feelings in Monozygotic Twins

Family socioeconomic status amplifies unique environmental influences on the dynamics of adolescent daily positive affective process

BACKGROUND AND OBJECTIVE

Affective processes as complex dynamical systems happen in people's daily lives. Affective dynamics characterizing unique features of individual affective systems are linked with long-term developmental outcomes. This study investigated genetic and environmental contributions, and the moderation by family socioeconomic status (SES), to two affective dynamics characterizing affective system sensitivity to the relative levels and change in affect, respectively.

METHODS

Using a sample of 490 17-year-old twins (41.1% males, 93.9% White) in a 40-day-long daily diary design, dynamical systems modeling estimated individual affective dynamics of positive and negative affect. Twin modeling examined genetic and environmental contributions to affective dynamics as well as the moderation of SES.

RESULTS

For both positive and negative affect, system sensitivity to the relative levels of affect was predominantly under unique environmental influences with negligible genetic influences; system sensitivity to the change in affect was affected by both genetic and unique environmental influences. SES amplifies unique environmental influences on sensitivity to the change in positive affect.

CONCLUSIONS

These findings highlight different genetic and environmental origins of different adolescent affective dynamics in their daily lives, and suggest that macro contexts could influence micro timescale affective dynamics.

Genetic and Environmental Influences on Adolescent Emotional Inertia in Daily Life

Emotional inertia represents the extent to which individuals' emotions tend to carry over from one time point to the next. High emotional inertia indicates low emotion regulation ability and has been associated with psychological maladjustment and mood disorders. However, the extent of genetic influence on emotional inertia, particularly in adolescents, is largely unknown. The current study examined genetic and environmental influences on individual differences in emotional inertia. This study followed a sample of 447 17-year-old same-sex UK twins (41% males) with an innovative intensive longitudinal daily diary design that captured their intra-individual emotion fluctuations over one month. Adolescents reported their positive and negative emotions once a day consecutively for up to 40 days. Time series analyses were used to construct emotional inertia and classical twin analyses were used to disentangle its genetic and environmental influences. The results showed that inertia for positive emotion was only modestly heritable and inertia for negative emotion showed no heritability at all. Both measures showed predominantly non-shared environmental influences. These findings highlight the importance of unique environmental influences in shaping individual differences in how well adolescents regulate their emotions and how easily they move from one emotional state to another in daily life. The importance of identifying specific environmental influences on emotional inertia is discussed, and suggestions of what those influences might be are offered.