Entrepreneurs are largely born rather than made, research suggests.
Sir Alan Sugar: A genetic success?
A UK-US study has found our genes are crucial in determining whether we are entrepreneurial and likely to become self-employed.
It found nearly half of an individual's propensity to become self-employed is due to genetic factors.
And, contrary to previous beliefs, family environment and upbringing have little influence on whether a person becomes self-employed or not.
The other factors which did play a significant role were random life events, such as being made redundant, winning a large sum of money, or a chance meeting.
The study was carried out by the Twin Research Unit at St Thomas' Hospital, London, the Tanaka School of Business at Imperial College, London and the US Case Western Reserve University.
The researchers examined self-employment in 609 pairs of identical twins and 657 pairs of same-sex non-identical twins in the UK.
Identical twins share all their genes while non-identical twins share, on average, about half.
The rate of entrepreneurship among twins was the same as across the general population.
But researchers looked at whether one twin being an entrepreneur increased the chance of their co-twin becoming an entrepreneur.
By comparing the difference in similarity rates between identical and non-identical twins they are able to establish the importance of genetic and environmental factors.
The similarity rate within the identical twins group was greater than for the non-identical twin group which suggests that genes are important.
Professor Tim Spector, director of the Twin Research Unit, said: "This relatively high heritability suggests the importance of considering genetic factors to explain why some people are entrepreneurial, while others are not.
"The research is important for business schools and employers who in the future could identify ways of selecting those who were most likely to succeed."
Professor Spector said there was evidence to show that genetic factors influence a variety of business-related areas, from job satisfaction to vocational interests.
However, he said the role of genetic factors in explaining the tendency of people to engage in entrepreneurial activity has not been explored.
"Although entrepreneurs are vital to the economy, as they create wealth and jobs, no-one knows precisely what drives people to become an entrepreneur.
"Until now, it has been assumed that the tendency to engage in entrepreneurial activity is explained by learned individual difference or factors relating to a person's situation."
The researchers say genetics is likely to determine whether a person has traits vital to being a successful entrepreneur, such as being sociable and extroverted.
Simon Briault, of the Federation of Small Businesses, said: "You do need to have a certain natural spark to be successful in business, and that is probably something you are born with.
"But after that it takes a lot of hard graft."
John Cridland, CBI Deputy Director-General, said: "If half of a person's propensity to become self-employed is due to genetic factors then half is caused by other influences and it is vital that the proper education and entrepreneurial support schemes are in place to enable them to blossom."