stay away from guys with long thumbs (like literally i just searched about what causes it and i think it connects to cdh13 and maoa gene which is also known as serial killer gene, like even in ottoman empire it was believed that people with long thumbs had serial killer tendency)
not technically a serial killer gene but maoa gene causes aggression like on a higher level than normal and it was found that majority of serial killers do have the maoa gene, it's usually associated with psychiatric disorders
