How does optimism suppress immunity? Evaluation of three affective pathways

Area of Science:

• Psychoneuroimmunology
• Social Psychology

Background:

• Prior research suggests a link between optimism and poorer immune function under stress.
• The psychological mechanisms mediating this relationship remain incompletely understood.

Purpose of the Study:

• To investigate the relationship between optimism and cellular immunity in first-year law students.
• To explore the role of goal conflict and affective states in mediating optimism's impact on immunity.

Main Methods:

• Longitudinal study of 46 first-year law students.
• Assessed delayed-type hypersensitivity (DTH) responses as a measure of in vivo cellular immunity.
• Examined the moderating effect of relocation (reducing goal conflict) and the mediating role of affect.

Main Results:

• When relocation reduced goal conflict, optimism predicted larger DTH responses (enhanced immunity).
• When students did not relocate, increasing goal conflict, optimism predicted smaller DTH responses (poorer immunity).
• Distress, engaged affect, and fatigue did not mediate the observed effects, though they independently influenced immunity.

Conclusions:

• The impact of optimism on cellular immunity is context-dependent, influenced by goal conflict.
• Relocation, by reducing goal conflict, may buffer against the negative immune effects of stress for optimistic individuals.
• Further research is needed to explore alternative pathways like effort or self-regulatory depletion.