Positivity Effect

In psychology and cognitive science, the positivity effect is the tendency of people, when evaluating the causes of the behaviors of a person they like or prefer, to attribute the person's inherent disposition as the cause of their positive behaviors and the situations surrounding them as the cause of their negative behaviors. The positivity effect is the inverse of the negativity effect, which is found when people evaluate the causes of the behaviors of a person they dislike. Both effects are attributional biases.

Both older and younger adults process emotional data over neural data. However,age-related valence reversal in processing emotional data is often observed.

The term positivity effect also refers to age differences in emotional attention and memory. Studies have found that older adults are more likely than younger adults to pay attention to positive than negative stimuli (as assessed by the dot-probe paradigm and eye-tracking methods). In addition, compared with younger adults' memories, older adults' memories are more likely to consist of positive than negative information and more likely to be distorted in a positive direction. This version of the positivity effect was coined by Laura L. Carstensen's research team.

Research shows an age-related reversal in the valence of information the most active within the medial prefrontal cortex (MPFC). In younger adults, more MPFC activation was found negative compared to positive stimuli. Results for older adults demonstrated more MPFC activity when subjected to positive compared to negative stimuli.

However, the positivity effect may be different for stimuli processed automatically (pictures) and stimuli processed in a more controlled manner (words). Compared to words, pictures tend to be processed more rapidly and they engage emotion processing centres earlier. Automatic stimuli are processed in the amygdala and dorsal MPFC, whereas controlled stimuli are processed in the temporal pole and ventral MPFC. Compared to younger adults, older adults showed less amygdala activation and more MPFC activation for negative than positive pictures. The opposite pattern was observed for words. Although older adults showed a positivity effect in memory for words, they did not display one for pictures. Thus, the positivity effect may arise from ageing differences in MPFC use during encoding.