You don't need big cojones to make it, but it helps

Integrity is essential to good science but it can too easily be lost in the pursuit of a career, writes Tim Birkhead, the first of our new columnists.

Tom Wolfe's bestseller The Right Stuff , published in 1979, described the extraordinary suite of psychological and physiological traits needed to become an astronaut. Few made it and, for those who did, the risks were enormous. So what made them do it? Being an academic researcher is only slightly less dangerous -and to survive and succeed also requires a special set of traits.

The following are the most important: (1) integrity; (2) intelligence and imagination; (3) tenacity; (4) a critical sense; (5) competitiveness; (6) the ability to communicate; (7) knowledge of your subject; (8) testicles.

Yes, testicles. Being male undoubtedly makes it easier to be a scientist.

It shouldn't, but it does.

As an aspiring researcher you need all (or nearly all) these attributes to succeed. Missing even one may hamper you, although to some extent they trade-off against each other. If you are lucky enough to have the intelligence of Einstein or Newton you can probably survive without the rest.

Integrity is probably the most important and essential for a scientist's credibility: even a whiff of dishonesty can mar a career. Scientists talk about finding the "truth" -discovering, usually by means of hypothesis testing, about the way the world is. The problem is that dishonesty in science is a continuum that runs from overinterpretation of data through to downright fraud.

The full range of views is expressed in two papers published in American Scientist . Lewis Branscomb in "Integrity in science" (1985) promotes a hard-nosed Popperian approach: if you cannot falsify your hypothesis, you are not doing good science. James Woodward and David Goodstein, on the other hand, say in "Conduct, misconduct and the structure of science" (1996) that we need mavericks to challenge the research establishment.

In a way both views are right -but in my opinion the first is often too strict and the second too sloppy. Which view you tend towards will depend on your personality and possibly your supervisor's approach to science. If you follow Branscomb's lead, progress might be tough.It is easy to mistakenly falsify a hypothesis and risk throwing the baby out with the bath water. On the other hand, if you follow Woodward and Goodstein's lead too closely you risk becoming what I call a "career scientist" -someone who ranks their career over their integrity. The physicist Jan Hendrik Schön at Bell Labs in the US, who falsely claimed to have created transistors out of single molecules, is an extreme example.

Once exposed, downright fraud is easy to deal with. More difficult are those novel or controversial ideas that might lead to a paradigm shift. In the late 1980s, Robin Baker (then of Manchester University) proposed the "kamikaze sperm hypothesis" to account for the remarkable diversity of sperm types in human ejaculates. A great idea, but one that failed to stand up to (anyone else's) scrutiny.

Another example is Bjørn Lomborg's notion that that there is no global environmental crisis: the extinctions going on around the world are nothing to worry about, he says. Such an outrageous idea is a great way to place yourself in the limelight, but few environmentalists believe him.

The point about career scientists is that they don't necessarily believe what they say; they adopt a viewpoint to promote their career. The pressure for young scientists to succeed -to get a paper in Nature or Science - may tempt some of them down this path. Beware!

The dividing line between sloppiness and innovation is a thin one. The crucial safeguard is, of course, putting your novel ideas to the test yourself and then having the cojones to tell the truth. It will hurt if your lovely idea proves to be nonsense, but that's the way progress is made.

Science is a social enterprise and what we do has to stand up to scrutiny.

At the end of the day, honesty is the best and only policy.

Tim Birkhead is professor of zoology at the University of Sheffield.