Heat increases anger also, air conditioning helps. In fact there are lots of known triggers of anger, being lied to, being betrayed, having possessions stolen,

Heat increases anger also, air conditioning helps. In fact there are lots of known triggers of anger, being lied to, being betrayed, having possessions stolen, getting yelled at in your workplace, losing a bet, losing a contest, feeling pain, being made fun of, being publicly humiliated, stormy weather (maybe related to pain from joints), withdrawal from drugs, steroids (roid rage), getting cut off in traffic, almost dying, having someone you love almost die or actually die, and lots more. Not all easy to fix or avoid, but some of them like stopping steroid use or treating pain can reduce anger. It would be interesting to see a catalog of everything known to trigger anger. Some causes are obviously emotional, some are obviously chemical, some physical (hitting your thumb with a hammer).