The feeling is mutual: A randomised controlled trial testing the positive body image process of reciprocity among close friends.

This study investigated the positive body image process of reciprocity and tested whether promoting positive body image can improve one's own and the others' body image. To this end, 124 pairs of female friends (N = 248) were randomised to the experimental or control group. Within each pair, friends were randomised to be the "letter writer" or "letter receiver." Letter writers wrote a letter expressing appreciation for their friend's body functionality (experimental group) or for their shared memories (control group) and read their letter to their friend. Body appreciation, functionality appreciation, and self-objectification were measured at pretest, midtest (after letter writing), and posttest (after reading). Letter writers in the experimental group reported higher body appreciation and lower self-objectification at midtest and posttest, and higher functionality appreciation at posttest, compared to the control group. Further, both groups reported higher body appreciation and functionality appreciation from midtest to posttest. Similarly, letter receivers in both groups reported higher body appreciation and functionality appreciation from midtest to posttest, and letter receivers in the control group reported decreased self-objectification. The findings suggest that promoting positive body image can improve one's own and others' body image, but the effects of the control activity must be considered.