"Measuring the distribution of spitefulness" - link

I always say, never underestimate the power of Spite.

This method reveals that the majority of individuals exhibit consistent (non-)spitefulness over time and that the distribution of spitefulness is bipolar: when choosing whether to be spiteful, most individuals either avoid spite altogether or impose the maximum possible harm on their unwitting victims.

To the extent that this holds up, it would be quite useful in a predictive sense.

Here is a rather curious paper describing psychology researchers' attempts to investigate "spitefulness" - I think they define spitefulness roughly as "hurting others without any benefit to oneself".

Does this include the subset "vindictiveness"? That is, "hurting others without any benefit to oneself when done against those who have previously hurt that which you care about". I endorse that subset as respectable, sometimes practical and even sometimes virtuous. Sometimes it is even heroic.

As an example, if I am playing a strategy game and an ally breaks an alliance in violation of whatever explicitly specified termination conditions we had arranged I will be 'spiteful'. That is, I will assign some degree of value to doing harm to that enemy above and beyond whatever is useful for my future success. The spite (vindictiveness) may be overridden by other priorities if there is still a chance for me to win the game. Being the type of person who is vindictive in this manner (and easy to predict) can be useful even though at the time of the vindictiveness it can be too late to help.