Is it time to update and expand training motivation theory? A meta-analytic review of training motivation research in the 21st century.

Colquitt et al. 2000, 85, p. 678) integrative theory based on meta-analysis and model testing has served as the foundation for our understanding of training motivation.

Friends With Performance Benefits: A Meta-Analysis on the Relationship Between Friendship and Group Performance.

The current article examines if, and under which conditions, there exists a positive relationship between working with friends and group performance. To do so, using data from 1,016 groups obtained from 26 studies, we meta-analyzed comparisons of the performance of friendship groups versus acquaintance groups. Results show that friendship has a significant positive effect on group task performance (Cohen's d = 0.