Latest study found how birthday years that end with 9 affects people's lives.

Many researchers believe that people make the worst decisions of the lives during middle age. However, a study conducted by the researchers at the University of California, Los Angeles (UCLA) and New York University suggests that people can make significant decisions, good or bad, at age 29, 39, 49 and so on.

This is the first study determining the fact that people try to understand the meaningfulness of their lives as they approach a new decade in chronological age, irrelevant of the countries they live in or the cultures they follow.

The researchers nicknamed the people in this category as "9-enders" and suggest that these people are more likely to make big decisions in their lives when compared to people with birthday years ending with other digits.

"When people are facing these new decades, that's when they start to step back and question essentially the meaningfulness of their lives," says Hal Hershfield, a marketing professor at UCLA trained as an experimental social psychologist, who is also the co-author of the study.

Hershfield reveals that he and Adam Alter, co-author of the study, came up with the idea of the strange study while discussing greeting cards and the hype some people create when they are about to enter a new decade of their life.

These years are not very significant such as getting married; getting a driver's license, getting to vote or more but these milestone years may play tricks on the minds of many people.

The researchers collected data from the U.S. Centers for Disease Control and Prevention (CDC), AshleyMadison.com - a website for extramarital affairs and Athlinks.com - an athlete website.

The study found that suicide rate for 9-enders was higher than people with other digits of birthday years. 9-enders were also found to be faster runners in marathons, which suggests that they trained harder before entering a new decade in life.

The study also found out of the 8 million men registered on AshleyMadison.com about 1 million were 29, 39, 49 or 59.

Hershfield explains that while approaching a new decade many people tend to look back and assess their life. These people may have many questions about their life for which they are seeking answers to and this is not abnormal. Some people want to assess the choices they had taken in the past and want to do things that they could not do.

Some experts believe that the study is well thought as it examines psychological truth using real data.

The study has been published in the journal Proceedings of the National Academy of Sciences (PNAS).