The problem with saying something hurtful during a heated conflict is that you can damage your relationships because you

you probably do not have self-control and can do or say things you would regret later.

Explanation: heated arguments and quarrels is of course something that happens and sometimes we cannot avoid it. Mature people, people trained in psychology should avoid them or should be at least cautious and let the other part take more active role. During such arguments shadow part of a person appears, primitive emotions takes control and people usually reveal that part of themselves they usually control and hide. Heated arguments constitute a good opportunity to get to know others because masks are usually falling down.

i got 3,4 and 5 as an answer

answer; overt behavior;