We’ve all been there. We see something online that we want, we hit the “purchase” button — and then wish we hadn’t. Why are we so fickle?

With the explosion in e-commerce, more and more of us are doing our shopping online, and shipping companies like UPS say returns of those items are at an all-time high.

And while such buyer’s remorse might have been triggered simply because people made bad buying decisions, experts think there’s something more primitive at work — namely, we’re less connected to items bought online because we can’t touch them first.

A recent study by Bangor University found that messages delivered via snail-mail leave a deeper and longer-lasting impression than when that same message is received online. Brain imaging showed that just touching the paper triggered an emotional response that led to a stronger bond, and researchers feel that could in turn lead to a sense of possession.

In other words, touching an item first makes us feel more strongly about owning it. And since we can’t do that when we’re shopping online (well, yet anyway), we don’t feel as connected to the things we buy that way — and are more likely to regret those purchases later on.