What it is
We have the tendency to view two options as more distinctive when we evaluate them together than we do when we evaluate them separately.
Why it happens
Our predictions of what will make us happy don’t always turn out to be accurate. This disconnect, in combination with our tendency to compare specific parts of the options we’re given, rather than form holistic impressions of each option on its own, give rise to distinction bias.
Example 1 – Distinction bias and reward
When we evaluate two options simultaneously, we magnify the differences between them and think they matter more than they actually do. Hsee and Zhang6 illustrated this in a study where participants in one condition had to remember a past failure and were rewarded with a greater amount of chocolate and participants in a second condition had to remember a past success and were rewarded with less chocolate. Participants predicted that the amount of chocolate they got would influence their mood, but it did not. Their experience of the task was influenced by the kind of memory they remembered. The difference between the chocolates was irrelevant.
Example 2 – Choosing a new home
When looking for a new place to live, we often compare our options, which can cause us to overvalue the differences between them. This can lead to us spending more money for something that we thought was worth it, but that turns out to be not all that important.
How to avoid it
Instead of evaluating our options simultaneously, we should look at them separately. This will make the small qualitative differences between them less obvious and allow us to make a decision unimpeded by distinction bias.