Maybe cause you cut their genitals without consent, which causes longterm changes to the brains fight or flight response which causes them to suffer & become more violent:

Every country where men are circumcised strongly correlates with increased violence, misogyny, crime rates, suicide and "toxic masculinity" (forcing other men to fit in to their world view of how a man should be, which is where the term actually comes from)

Sources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7702013/

https://pubmed.ncbi.nlm.nih.gov/31080593/

https://www.psychologytoday.com/intl/blog/moral-landscapes/201501/circumcision-s-psychological-damage

https://www.news-medical.net/news/20201217/Study-shows-infant-circumcision-has-delayed-psychological-complications.aspx

https://www.omegapediatrics.com/psychological-effects-infant-circumcision/

https://www.scirp.org/journal/paperinformation?paperid=55727

https://circumcision.org/circumcision-factor-violence-against-women/

https://pubmed.ncbi.nlm.nih.gov/23374102/

https://pubmed.ncbi.nlm.nih.gov/22114254/

Emotional lethargy and inappropriate anger are possible long-term effects of circumcision that warrant investigation. Reduced capacity for emotional expression or the 'numb' response is a more likely PTSD symptom with increased time after the traumatic event.

https://soph.uwc.ac.za/project-item/understanding-the-mental-health-disorders-among-males-who-have-been-traditionally-circumcised/

https://link.springer.com/chapter/10.1007/978-1-4757-3351-8_12

https://www.cirp.org/library/psych/goldman1/

https://www.doctorsopposingcircumcision.org/for-professionals/psychological-impact/

https://www.researchgate.net/publication/374846045_Male_Circumcision_Impacts_on_Sexual_Function_Psychological_Well-Being_and_Overall_Quality_of_Life_in_Ghana_and_the_Sub-Saharan_Africa_A_Scoping_Review