“…The mean quality score of internal validity was 2.3/5 ( SD = 1.0). Nine (43%) of the studies (Bybee, Ennis, & Zigler, ; Carroll, Friedrich, & Hund, ; Jones, ; Leahy, Balla, & Zigler, ; Mueller & Prout, ; O'Byrne & Muldoon, ; Stager, Chassin, & Young, ; Szumski & Karwowski, ; Yun & Ulrich, ) met more than half of the internal validity criteria. More precisely, as illustrated in Table , the most frequently satisfied criteria were a clear presentation of the self‐concept assessment procedure (16/21, 76%) and the incorporation of a correction for the confounding effect of sex (13/21, 62%).…”