Modeling Intraindividual Dynamics Using Stochastic Differential Equations: Age Differences in Affect Regulation.
Life-span theories of aging suggest improvements and decrements in individuals' ability to regulate affect. Dynamic process models, with intensive longitudinal data, provide new opportunities to articulate specific theories about individual differences in intraindividual dynamics. This paper illustrates a method for operationalizing affect dynamics using a multilevel stochastic differential equation (SDE) model, and examines how those dynamics differ with age and trait-level tendencies to deploy emotion regulation strategies (reappraisal and suppression).



Univariate multilevel SDE models, estimated in a Bayesian framework, were fit to 21 days of ecological momentary assessments of affect valence and arousal (average 6.93/day, SD = 1.89) obtained from 150 adults (age 18-89 years)-specifically capturing temporal dynamics of individuals' core affect in terms of attractor point, reactivity to biopsychosocial (BPS) inputs, and attractor strength.



Older age was associated with higher arousal attractor point and less BPS-related reactivity. Greater use of reappraisal was associated with lower valence attractor point. Intraindividual variability in regulation strategy use was associated with greater BPS-related reactivity and attractor strength, but in different ways for valence and arousal.



The results highlight the utility of SDE models for studying affect dynamics and informing theoretical predictions about how intraindividual dynamics change over the life course.
Department of Human Development & Family Studies, Pennsylvania State University, University Park.
Julie
J
Wood
Department of Human Development & Family Studies, Pennsylvania State University, University Park.
Zita
Z
Oravecz
Department of Psychology, Humboldt University, Berlin, Germany.|German Institute for Economic Research (DIW), Berlin, Germany.
Nina
N
Vogel
Department of Human Development & Family Studies, Pennsylvania State University, University Park.
Lizbeth
L
Benson
Department of Human Development & Family Studies, Pennsylvania State University, University Park.
Sy-Miin
SM
Chow
Department of Psychology, Pennsylvania State University, University Park.
Pamela
P
Cole
Department of Kinesiology, Pennsylvania State University, University Park.|Department of Preventive Medicine, Northwestern University, Chicago, Illinois.
David E
DE
Conroy
Department of Psychology, Pennsylvania State University, University Park.
Aaron L
AL
Pincus
Department of Human Development & Family Studies, Pennsylvania State University, University Park.|German Institute for Economic Research (DIW), Berlin, Germany.
Nilam
N
Ram
D000293:Adolescent; D000328:Adult; D000339:Affect; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D005260:Female; D006801:Humans; D007206:Individuality; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D013269:Stochastic Processes; D055815:Young Adult
Affect dynamics; Emotion regulation; Experience sampling; Intraindividual variability; Longitudinal analysis