Suppose our minds have a hot state and a cool state.  In the cool state we are rational and make calculated tradeoffs between immediate rewards and payoffs that require investment of time and effort.  But when the hot state takes over we abandon deliberation and just react on instinct.

The hot state is there because there are circumstances where the stakes are too high and our calculations too slow or imperfect.  You are being attacked, the food in front of you smells funky, that bridge looks unstable.  No matter how confident your cool head might be, the hot state grabs the wheel and forces you to do the safe thing.

Suppose all of that is true.  What does that mean when a situation looks borderline and you see that instincts haven’t taken over?  Your cool, calculating head rationally infers that this must be a safer situation than it would otherwise appear.  And you are therefore inclined to take more risks.

But then the hot state better step in on those borderline situations to stop you from taking those excessive risks.  Except that now the borderline has moved a little bit toward the safe end.  Now when the hot state doesn’t take over it means its even more safe, etc.

And of course there is the mirror image of this problem where the hot state takes over to make sure you take an urgent risk.  A potential mate is in front of you but the encounter has questionable implications for the future.  Physical attraction receives a multiplier.  If it is not overwhelming then all of the warning signs are magnified.