Translated into human terms, look at it like this: You have a choice, you could get a guaranteed $2000 or have a 50% chance of getting $1000 and a 50% chance of $3000.

To gamble or not to gamble - which option would you choose?

Most people will go for the safe option - they take the $2000. That is also what monkeys do.

So far so good. Apes and monkeys are, after all, our nearest animal relatives. We share a common evolutionary history. However, once the experiment was adjusted so that the monkeys had the same options but from a different starting point, something fascinating happened.

Professor Laurie Santos explains “So the monkeys come in and it looks like both experimenters [are] kind of holding three [grapes] so this monkey brain is probably thinking ‘oh there’s a chance to get three.’ One guy is safe, he does the same thing every time...the monkey trades with this guy [and] he’s holding three but he takes one away and gives the monkeys two so it’s kind of a sure loss - a small loss but a sure one,” says Santos. “The second guy is risky - sometimes he gives the monkeys all three but sometimes he takes two away and only gives the monkeys one.”

Again, let’s look at that another way: You start with $3000, now you have a choice. Either you take a guaranteed loss of $1000 leaving you with only $2000 or you gamble. If you gamble half the time, you will lose $2000 leaving you with just $1000 but half the time you will not lose anything. What would you do?

Most people will gamble and go for the riskier choice. Surprisingly, so do the monkeys. The thought of losing out is so painful that they will risk a bigger loss just for a chance of no loss.

When stocks and shares crash or house prices collapse, you might expect people to become more cautious. In fact, they take more risks. People will hold onto stock that is losing value, speculating the price will rise again, because we can’t bear the thought of having less than we have now. This is loss aversion.