While research repeatedly finds that intimate partner violence (IPV) rates are elevated in same-gender relationships (SG-IPV) and in the relationships of sexual minorities (SM-IPV), it is less clear whether this abuse tends to be “unidirectional,” with one perpetrator, or “bidirectional,” with two perpetrators. This article offers a systematic review of the SG-IPV and SM-IPV (SGSM-IPV) directionality literature, including calculating weighted and unweighted prevalence rate estimates, as well as a critical assessment of methodological limitation and IPV motivation research. Findings indicate that, while approximately half of those who experience an SGSM-IPV relationship have both used and received abusive tactics—similar to findings in the literature on different-gender IPV and IPV in the relationships of heterosexuals—labeling this as “mutual abuse” may mask complexities in the data, including, but not limited to a dearth of relationship-level analysis, a lack of standardization in how SGSM-IPV is operationalized, and newly emerging research on the prevalence of self-defense as a motive in bidirectional SGSM-IPV. Directions for future research are discussed
