R. Ila'i said: By three things may a person's character be determined: By his cup,(koso) by his purse (kiso) and by his anger (kaso); and some say: By his laughter (sachko) also.
The Hebrew alliteration works to hold this epigram together. But there is great truth there as well. How one handles drink, i.e. moderation or excess and attitude when constraints are lifted; how one deals with money especially charitable giving; how one relates to others even in anger; and the ability to laugh, even at one’s self; all tell us the truth about a person’s character.