Our memories are sometimes unreliable.

And though we still don't know precisely what causes this fallibility on a neurological level, research has highlighted some of the most common ways our memories diverge from what actually happened.

The mall study highlights how we can incorporate information from outside sources, like other people or the news, into our personal recollections without realizing it.

This kind of suggestibility is just one influence on our memories.

Take another study, in which researchers briefly showed a random collection of photographs to a group of participants, including images of a university campus none of them had ever visited.

When shown the images three weeks later, a majority of participants said that they had probably or definitely visited the campus in the past.

The participants misattributed information from one context — an image they'd seen — onto another — a memory of something they believed they actually experienced.

In another experiment, people were shown an image of a magnifying glass, and then told to imagine a lollipop.

They frequently recalled that they saw the magnifying glass and the lollipop.

They struggled to link the objects to the correct context— whether they actually saw them, or simply imagined them.