The average person keeps 13 secrets and 5 of those have never been shared

Everyone has secrets - and now we might know just how many.

A new study led by professor of management at Columbia Business School Michael Slepian, has looked into the secret-keeping habits of thousands of people - as well as examining a grand total of 13,000 secrets between them.

The research, published in the Journal of Personality and Social Psychology, looked at the secrets collected over the course of 10 previous studies to come up with 38 common categories, ranging from cheating on a test to hiding their sexuality to sleeping with another's spouse.

After breaking down the categories, the researches asked 2,000 participants to number the common secrets they are keeping that fit into the categories.

In the end, they found that the average person was carrying 13 of the 38 secrets at any one time. 

They also discovered that five of those 13 secrets have never been shared with another person.

The most commonly held secrets involved what researchers termed 'extra-relational thoughts', as well as sexual behavior, lying, and romantic desire. The researchers defined a secret as something they intended to keep from others. 

The common secrets that people were less likely to keep to themselves were abortion, marriage proposals and sexual orientation. 

In addition to the number and types of secrets people keep, the researchers also looked into the way keeping them affects behavior and health. 

People become more concerned about the secrets they are keeping when they are alone than when actively hiding them from people they are interacting with.  

'We actually don’t encounter many situations where we have to hide our secrets relative to all the times a secret will just come into our thoughts, and intrude upon our thinking,' lead researcher Michael Slepian told The Atlantic. 

He added that when people were thinking about their secrets, they also 'acted as if they were burdened by physical weight.'

Slepian suggests that the reason for this powerful effect is its presence as a goal that is never truly accomplished. 

'You might encounter a conversation where you have to conceal it, but there might always be future moments down the road where you have to conceal again,' he said.

Like other studies before it, the researches also found that keeping secrets can have detrimental consequences for a person's well-being. In particular, they examined how participants reported feeling inauthentic when they mused on the secrets that burdened them. 

The only way to keep yourself from feeling these negative thoughts, Slepian believes, is to just think about secrets less - given the study found that the secrets themselves didn't lower well-being, but rather the thought of them did.