A new study about the psychology of keeping secrets has categorised over 13,000 secrets.

For the purposes of the study, a secret was any information that a person intended to conceal from one or more individuals.

The study was first published in the Journal of Personality and Social Psychology in May, and was co-authored by Michael Slepian.

It built on his 2012 study which found that people who were distracted by a secret tended to judge tasks to be more arduous than they were in reality.

This warped perception even meant they thought a distance was further and the gradient of a hill steeper than was the case in reality.

Secrets we keep

1000 participants were asked to describe a secret they were keeping. These were then reviewed by a researcher, who manually created 38 broad categories into which these could fall.

For instance, stealing from a person known to you, and stealing from an organisation were put into the category 'theft'.

Distinctions were made between things like emotional infidelity (flirting), and sexual infidelity (cheating).

34 of these categories were listed in the study's appendix along with the questionnaire.

Harmed another person

Drug use

Habit/Addiction

Theft

Doing something illegal

Self-harm

Abortion

Trauma

Lie

Violate trust

Romantic desire

Romantic discontent

Extra-relational thoughts

Emotional infidelity

Sexual infidelity

Been the other woman/man in someone else’s relationship

Social discontent (disliking a friend)

Work cheating

Poor work performance

Marriage proposal (planning)

Surprise

Hobby

Hidden relationship

Family detail (something about your family kept secret)

Pregnant

Sexual orientation

Sexual behaviour

Not having sex

Preference (pretending to like something you don’t)

Belief or ideology

Finances

Employment (secret job)

Ambition

Unusual behaviour

Some secrets were so personal to a participant that they did not fit into one of the other categories.

13 Common Secrets

The study showed the compiled categories to a new set of participants.

On average each person currently was keeping at least 13 secrets from the list.

According to the study, at least five of them were ones they had never told to anybody.

The most common secrets:

60 per cent - a lie or financial impropriety

47 per cent - a violation of trust

33 per cent - theft, a hidden relationship, or discontent at work

Burden of secrets

The study found that secrets weigh on us, even when there's little danger that they will be uncovered.