We've all seen people do horribly selfish things. After they hog credit, leave a stingy tip, or shirk their responsibilities, these people often continue on blithely self-satisfied and apparently happy despite having behaved like absolute jerks. How do they manage to not feel awful about themselves? 

A new Yale study, recently published in the journal Nature, provides a simple but annoying answer: they just forget their own selfishness. These results are both an explanation of so much bad behavior and a reminder why it's not worth the effort to try and rehab your relationships with the self-absorbed in your business or personal life. 

How to act like a jerk and still feel OK about yourself 

To dig into how selfish people can live with themselves, a team of Yale psychologists and Swiss economists teamed up to design a series of simple experiments. In the lab and online they asked volunteers to divide up a pot of money among strangers. Later the subjects were asked to recall exactly how they had divvied up the loot. 

Even when the researchers paid participants to be honest, those who had handed out the stingiest amounts steadfastly refused to remember their selfishness. Instead, they falsely remembered being much more open handed. 

A follow-on experiment showed that participants were only foggy about their past selfishness when they had personally decided to act like a jerk. If they were instructed by the researchers to split the pot unequally, they remembered the amounts just fine. 

Taken together these experiments paint a clear and unflattering picture of what's going on in the minds of the selfish. Not only do they behave like jerks, but they avoid facing the fact of their own bad behavior by simply refusing to remember it. 

"When people behave in ways that fall short of their personal standards, one way they maintain their moral self-image is by misremembering their ethical lapses," Yale's Molly Crockett said, summing up the findings. 

A reminder from science: it's time to ditch the jerks 

What's the takeaway here? Mostly just a scientific explanation for a phenomenon that you've no doubt both witnessed and been annoyed by. But these results are also yet another reminder that trying to rehab or reason with those who treat others poorly is likely a huge waste of time. 

A parade of findings shows jerks are toxic to workplaces, cost companies money, make those they interact with them nastier too, and even contribute to th earlier demise of people forced to deal with them. Now you know they probably don't even remember the harm they've caused. It's one more reason not to let them into your company or your life.