Defaults can have unintended, even harmful outcomes. For example, the default to automatically play videos on Facebook can expose people to destructive imagery unless carefully curated. While auto-play is effective, adding a bit of friction isn’t always bad.
Spending on credit doesn’t seem to feel like spending. When we pay with cash, both the pleasure and pain parts of our brain light up. Yet only the pleasure part lights up when we spend on credit card. This could lead to over-spending.