There is light at the end of the tunnel for parents of big-headed teenagers, as a new study reveals how narcissism changes over time.

Scientists have found that key characteristics linked to narcissism – such as being full of yourself, sensitive to criticism or imposing your opinion on others – fall as we age.

Michigan State University looked at 747 people born between 1923 and 1969, from 13 years old to 77 years old.

Young adults were identified as the fastest-changing age group, though researchers say narcissism changes are lifelong and don't necessarily end at a particular age

'There's a narrative in our culture that generations are getting more and more narcissistic, but no-one has ever looked at it throughout generations or how it varies with age at the same time,' said William Chopik, associate professor of psychology and lead author.

'There are things that happen in life that can shake people a little bit and force them to adapt their narcissistic qualities.

'As you age, you form new relationships, have new experiences, start a family and so on.

'All of these factors make someone realise that it's not 'all about them'. And, the older you get, the more you think about the world that you may leave behind.'

The study suggests that some traits, such as having high aspirations, grow with age.

Researchers say the older you get, the more you think about the world that you may leave behind

However, the most significant moment in which a person's narcissism declines is when they land their first job.

Young adults were identified as the fastest-changing age group, though researchers say narcissism changes are lifelong and don't necessarily end at a particular age.

'One thing about narcissists is that they're not open to criticism,' Professor Chopik continued.

'When life happens and you're forced to accept feedback, break up with someone or have tragedy strike, you might need to adjust to understanding that you're not as awesome as you once thought.

'There's a sense in which narcissists start to realise that being the way they are isn't smart if they want to have friends or meaningful relationships.'

According to a Queen's University Belfast study from earlier this year, narcissism can lead to mental 'toughness'.

The university study of 700 people led it to conclude that narcissism appeared to increase mental resilience, which can offset symptoms of depression.