According to one recent study, the portfolio effect dominates:

You might expect that being prompted (primed) to think of yourself as a good person would make you more altruistic or moral – but, in fact, the exact opposite appears to be

the case. Primed to think about what a good person you are, your most

likely reaction is to think you’ve paid your morality dues and go on

about your business.

The underlying model is this:

According to a new study in Psychological Science,

humans engage in a process called “moral self-regulation.” Basically,

we’re constantly calculating the trade-off between being able to see

ourselves as good people and the cost of engaging in all that

non-advantageous goodness.