There is little that irritates scientists more than the idea of the "boffin". This century-old meme has at least two flavours: the befuddled, bespectacled, bad-hair-day (or no-hair-day) man, socially inept but somewhat cuddly (think Doc in Back To The Future); and there is the more sinister iteration: the equally dishevelled but cold, arrogant and/or mad male meddler, bent on no good (think Rotwang in Metropolis).

Neither of these versions is remotely flattering, and neither bears any resemblance to reality. If you came to visit me in my molecular biology lab, you'd certainly see the expected array of shiny microscopes, racks of tubes, glass beakers, steaming liquid nitrogen and even the odd white coat, but you'd mainly encounter a building full of very normal-looking people.

Because I'm a biologist, you'd see roughly equal numbers of men and women, mostly between the ages of 20 and 40-something. Our dress sense would range from casual to snappy: lots of T-shirts and jeans, but also a number of people making an effort, depending on what their plans were that evening. You wouldn't hear any maniacal laughter (unless it was ironic) though you would hear lots of banter, music, shop-talk and gossip. My friends in other scientific fields look similar, though disciplines such as physics, chemistry and maths tend to have fewer women.

Most of us are obsessed with the work – as people in many professions are – but we also know how to have a good time. Lab staff have probably looked and acted pretty much like this since the 1970s. So why does the boffin meme stubbornly persist?

I've made it one of my life's missions to eradicate boring old portrayals of scientists from our fiction. And, at one time, I was a firm believer that society-at-large had negative stereotypes about us scientists in their heads as well.

Nowadays, though, I'm starting to wonder if we scientists have got it wrong, that we are the ones with the outdated stereotypes of what everyone else thinks.

At a recent conference held in London, there was a lot of fretting about scientist stereotypes amongst the researchers present. People spoke about "draw-a-scientist" experiments in which children obligingly produce the classic male boffin image. Margaret Mead and Rhoda Métraux performed such experiments in 1957 (35,000 high school students), as did David Wade Chambers in 1983 (about 4000 children ranging in age from 5 to 11). Both researchers found that, compared with the beginning of the 20th century, the "mad" meme was fading in favour of an emphasis on government conspiracy and warfare – but the researchers were still pure boffins. Little had changed since Mead, Chambers found, except that about 1% of the girls (and only girls) would draw female scientists. Chambers, with his age range, was also able to pinpoint when stereotypes had set in: about age 7. By 2003, when Christopher Frayling carried out a similar, though very small, study (88 students aged 7-11), only a little more than half the drawings were stereotyped, and half of the girls drew females. Comparing these studies suggests that the boffin image might already be on the way out.

There is also a knee-jerk reaction amongst my colleagues that scientists are portrayed badly in films and on TV. But this simply is not true – not for the past few decades at least. In his entertaining book Hollywood Science, physicist Sidney Perkowitz sat through hundreds of films from the 20th century – from biopics to B-movies and blockbusters – and saw the evolution of on-screen scientists from Einstein-haired wild-eyed men through to today's industry standard: young, beautiful 20- or 30-somethings of both genders with glossy hair and trendy clothes. If they require vision correction, then it's largely designer spectacles.

I would argue, from my own viewing, that the 21st century has continued this trend. Think of Bridget Moynahan in I, Robot (2004), Will Smith in I Am Legend (2007), Chiwetel Ejiofor in 2012 (2009), Sigourney Weaver in Avatar (2009), Adrien Brody and Sarah Polley in Splice (2009) – and the entire cast of CSI and other forensics dramas on TV. The science itself may be outrageous, but its practitioners don't look like boffins. They have depth and humanity and they're even allowed to be sexy.

We've been living with these catwalk Hollywood scientists for nearly 20 years now but has this affected how people – both children and adults – view scientists? Though I can find no hard data on this, I think it's probably very likely. As images of scientists have to come from somewhere visual, where better than the big screen?

A deeper question is whether we even believe the old research data on perceptions anyway. Some of the authors of draw-a-scientist studies have pointed out the obvious drawbacks: if children believed that the task was to reproduce a recognisable scientist, they'd probably pull out all the stops with regards to stereotypes – much as all the children I know draw stylised houses with pointed roofs, paned windows and smoking chimneys. Children know that not all houses look like this, but that's part and parcel of the schema they hold for the concept of "house". So maybe these sketched boffins are not an accurate representation of their true understanding either.

The most important question is probably whether any of these stereotypes actually make a difference, beyond the ability to impress members of the opposite sex at parties. Christopher Frayling certainly has thought so, as he made it a key message in his 2005 book Mad, Bad and Dangerous?. But would a poor or cartoonish image actually impair the trust that people have in us in real life?

Scientists themselves seem to believe it would. If you'd eavesdrop on us down at our local pub, you might hear us worrying about misleading and negative imagery that may be holding us back from engaging productively with society, impairing public trust in us as messengers, and ultimately, in our message. And in a time when scientists have valuable input to add to debates about key issues such as the MMR vaccine or climate change, that reticence could have serious consequences.

But I suspect that our collective gut feeling that scientists aren't trusted is a stereotype too. In a recent Ipsos MORI poll, we didn't do too badly at all, being ranked 6th (65% trust) behind doctors (90%), teachers (86%), professors (78%), judges (78%) and the clergy (73%). If you remember that many scientist-spokespeople are professors as well, the trust is even higher. Maybe it's not brilliant, but we're still streets ahead of the police (59%), civil servants (44%), government ministers (22%) and – ouch – journalists (18%).

So why do scientists sense a lack of trust when it may not be justified? Most of our public debates have now moved online, and I think that we scientists get a disproportionate feeling of negativity from a small number of vocal and virulent people who frequent the comment threads of our newspaper sites, blogs and fora. Hell hath no fury like an anonymous conspiracy theorist with access to an internet connection. Maybe, instead, we should shake off the whole boffin thing as a minor annoyance, one that is possibly heading for extinction, and concentrate on what really matters: continuing to speak to the public about our work and showing them as best we can what it is we do – and why. With the current spending cuts looming, it's never been so important.