Two year olds are highly amusing, and even better, sometimes provide interesting insights into the science of decision-making. Take, for example, a certain two-year old I know who likes biscuits (well, most foods, but I think biscuits are a favourite). The bigger, the better – or at least in relative terms.
If you break a cookie in half, he always wants the bigger piece. Specifically giving him the smaller piece is usually met with the retort, “NO! BIG!”. Ok, so far, so unsurprising. He likes biscuits. He prefers more biscuit to less (economists would call it monotonic preferences, but enough of that). It’s sort of annoying if it’s your biscuit he’s hijacking, but not unusual behaviour for a small child.
What is interesting (and highly amusing) is the ability to use relativity to make him choose to consume a smaller piece. Take the half of the biscuit he rejected, snap it in half again, give him the bigger of the two resulting pieces. He gets just around a quarter of the cookie, but is completely satisfied – because it’s bigger than the other piece. It’s all about getting the bigger piece, and nothing to do with absolute amount of biscuit.
It’s an apparently universal decision-making trait. It’s exploited in marketing to get you to buy particular products (got a TV that isn’t selling well? Put it next to a TV that’s slightly inferior). Even slime-mould uses relative decision-making.
And that’s how to outwit a small child with the power of decision-making science.