Which battle will matter most in the general election campaign?

Unlike the last two general election campaigns, this one could actually affect the result. Labour went into the 1997 and 2001 elections so far ahead that only the degree of Conservative humiliation was in question. For the election on May 5th, that's not true: Labour's lead is just a few points. The oddities of the electoral system mean this should still bring a solid overall majority, but the Tories' chances of recovery are now great enough for them to be taken seriously.

Labour's small lead and the likely low turnout give the parties two clear tasks. The first is to reach waverers in the 100-odd seats that have a realistic chance of changing hands. The second is to persuade lukewarm supporters to get out and vote. That is particularly important for Labour, which has greater underlying support, but more disillusioned voters. To win those battles, the parties are fighting on two fronts: national and local-the air war and the ground war respectively.

Political parties are not allowed to buy advertisements in the broadcast media, so the air war chiefly involves politicians taking swipes at each other on national television. They can pull tricks, such as refusing to be interviewed with an opponent, or answering every question with a monologue on the campaign theme of the day. But the rewards are limited. The wavering, disillusioned or apathetic voters whom the parties most need to reach are those least likely to be persuaded by set-piece political blather on telly. An added problem for Labour is that their success in getting media coverage in the past eight years makes audiences even less receptive.

One way round this is to get party heavyweights on to normally apolitical programmes such as daytime chat-shows. Tony Blair recently gave a television interview to two ten-year-old boys. After asking him silly questions such as why he didn't just print more money to give to poor people, they thanked him for his time with gifts that included patriotic-themed panties for Mrs Blair. That may strike the political classes as cheesy, but party managers think it reawakens interest among disengaged voters.

A second tactic is to take questions from audiences of "real people", rather than from professional interviewers. Mr Blair was recently berated on live television by a woman from Cardiff who had resorted to pulling out her teeth herself because she couldn't find a publicly funded dentist. Such encounters might seem damaging to the point of masochism, but strategists reckon they make Mr Blair look in touch with the public, dispelling the notion that he is preoccupied by foreign affairs. And the public can, occasionally, be nice.

Text 6

Birdbrained

Are women naturally bad scientists?

In his three-and-a-half years in the job, the president of Harvard University, Larry Summers, seems to have upset a large number of people. First, he said students were getting too many "A" grades because of grade inflation (which was correct). Then he took on Cornel West, a black professor, over his dodgy extracurricular activities (again, Mr Summers had a point). Now he has suggested that one of the reasons women achieve less in science and maths is that they have less innate ability.

Mr Summers's comments were off the record; but he has since confirmed that he did draw attention to the possibility that innate differences, rather than social factors (such as education and treatment in the workplace) might have a role to play. This has drawn howls of complaint from the usual quarters. But, scientifically speaking, is he correct?

There is certainly evidence to suggest that the average male and female brains may be different, with men better able to "systemize" about the world and women better at "empathizing". So are we wired differently from birth?

Some clues come from a theory that autism is a developmental disorder that produces an "extreme male brain". Autism is up to four times more common in boys, and is thought to be caused by high levels of testosterone in the womb. Those who have it tend to be better at puzzles and pattern-related tasks than at verbal communication. Maybe males, with more testosterone in the womb, are simply better at non-verbal skills? A medical description of autism practically reads like a scientific job description. Clumsy and overwhelmed by the physical world, autistic minds are often far more comfortable with the virtual realms of maths, symbols and code.

However, even if geeks are naturally male, says Susan Ganter, executive director of the Association for Women in Science in Washington, DC (and a mathematician by training), it would not warrant Mr Summers's comments. Nobody knows to what extent such variations are actually important. They may well be a minor factor, while there are plenty of others that undoubtedly affect female success in science. One of these is that it is very difficult to return to science after a career break to have a child-something Mr Summers also talked about in his speech.

Worse, from a scientific viewpoint, Mr Summers may have compounded the problem by mentioning it. A slew of scientific research shows that if people are told they will fail, they will do so.

Text 7