Reference
Emily F. Hittner, Jacquelyn E. Stephens, Nicholas A. Turiano, Denis Gerstorf, Margie E. Lachman, Claudia M. Haase. Positive Affect Is Associated With Less Memory Decline: Evidence From a 9-Year Longitudinal Study. Psychological Science, 2020; 095679762095388 DOI: 10.1177/0956797620953883
At a glance
This large-scale longitudinal study shows that individuals with higher levels of positive affect have a less steep memory decline over the course of almost a decade. This result adds to a growing body of research on positive affect’s role in healthy aging. Although the study does not demonstrate a causal relationship, it opens up new pathways for research in multiple fields.
What is already known
Memory decline is a very common phenomenon, yet we know that there are a number of modifiable factors that allow us to prevent it and slow it down. Little is known about the impact of positive affect on memory, even though its benefits to physical health and healthy aging are known. What is meant by “positive affect”? Positive affect refers to the subjective experience of pleasant affective states, such as enthusiasm or joy, over shorter and longer time intervals. It is conceptually and empirically distinct from negative affect and other aspects of well-being (e.g. life satisfaction). The hypothesis of the study is that positive affect would be associated with less memory decline over time. This hypothesis could be supported by what we know from research on positive affect:
- From a physiological perspective, positive affect has been linked to more adaptive cardiovascular and immune functioning;
- From a behavioral perspective, positive affect has been associated with more adaptive health behaviors;
- From a social perspective, positive affect has been linked to better social relationships;
Design and Method
The study – a large-scale longitudinal study involving a sample of about 1000 middle-aged and older U.S. adults – was conducted over a period of 19 years, with 3 periods of assessment. In each assessment, participants reported on a range of positive emotions they had experienced during the past 30 days. In the final two assessments, participants also completed memory tests. Positive affect was assessed using two measures: a measure that combined items from the Affect Balance Scale (ABS; Bradburn, 1969) and the General Well-Being Schedule (GWB; Fazio, 1977) and an abbreviated version of the Positive Affect subscale of the PANAS (Watson et al., 1988). Memory was measured as part of the 20-min Brief Test of Adult Cognition by Telephone (BTACT; Lachman et al., 2014). The researchers analyzed the association between positive affect and memory decline, controlling for age, gender, education, depression, negative affect, and extraversion.
Main Findings
The study showed a progressive memory decline, as the ages of the sample subjects increased, and showed that individuals with higher levels of positive affect had a less abrupt memory decline over nearly a decade. These results extend our knowledge of the already known benefits of positive affect.
Limitations
The study has some limitations that could be corrected with more granular data, collected more frequently, that assesses other aspects of memory functioning. It is not possible to know if the results could be generalized to other contexts, to a more heterogeneous sample and to other countries. It may also be useful to examine positive affect using laboratory based and experience-sampling approaches.
What’s New and what are the prospects
The main strengths of this study are the use of a gold-standard measure of positive affect and the large-scale sample. As the study shows only an association and not a causality, future research could be oriented to clarify the mechanisms and pathways linking positive affect and memory (physical health, neurophysiological changes, adaptive health behaviors and social relationships). Another direction for future research could be to evaluate, through randomized trials, the effect of positive affect interventions (prevention or screening) on memory decline.
