Ah! What to wear for a Monday at work? It’s a question as old as work itself and we at MR PORTER of course like to think we can help you out with such matters sartorial. So, if you’ve ever wondered why your ineffective colleague made it to the C suite (that’s a new Americanism, before you write in, meaning staff with a C in their title – chief this, chief that, and so on) before you did, you should look beyond his latest presentation and instead to his suit, shoes and glasses. Because, in a revelation completely at odds with what your parents had you believe – it’s what’s on the outside that counts.

That’s according to new book Messengers by psychologists Mr Joseph Marks and Mr Stephen Martin. Identifying two types of effective messengers: hard messengers, who win influence by getting ahead of others, and soft messengers, who achieve influence by getting along with others. Each group has four characteristics, with “hard” messengers inferring socio-economic status, competence, dominance and attractiveness, and “soft” inferring warmth, vulnerability, trustworthiness and charisma.

How you express these qualities – and, spoiler alert, it’s advisable to encompass all of them – is less about what you say and more about how you present yourself. With that in mind, we asked Mr Marks to explore the psychology of a successful work wardrobe.

A snap judgment occurs within 50 milliseconds of meeting. “We will often infer, from a scant few moments together, who is confident, warm and enthusiastic, in control, dominant, trustworthy, likeable, authoritarian or [an] expert,” says Mr Marks. We look for clues to a person’s authority – and just like a doctor’s white coat signals medical expertise, a well-cut TOM FORD suit can convey that you know how to handle yourself in the boardroom. Your footwear matters, too: a US research team found people accurately predicted the personal characteristics of a stranger by seeing nothing other than photographs of their shoes. “Folders and important-looking papers that executives clutch as they walk purposefully around their offices” are also a useful tool “to enhance perceptions of their importance,” says Mr Marks.

Conspicuous consumption is a term that refers to “paying a premium for goods and services in order to impress others and boost your prestige”. It might not be the subtlest of approaches, but it works: in a 2011 study, Dutch shoppers were asked to rate the socio-economic status of a man based purely on his photo. In the photos where the man wore a Tommy Hilfiger T-shirt, he was judged as wealthier and of higher socio-economic standing. Another study by the same team found drivers of luxury cars were less likely to be hooted at by fellow motorists – even if they were holding up traffic. Similar results can be had in the office when you put on your Prada glasses, or reach into your Gucci briefcase. “However, if you’re seen as self promoting and actively showing off your status, then people will respond with what we call hostile envy,” says Mr Marks. “Actions need to be balanced with warmth and humility.”

You don’t just need to wear a suit to impress – take Mr Mark Zuckerberg’s uniform of T-shirt, hoodie and jeans. “It gives him more power because it enables him to say, ‘I’m so powerful I can do what I like and I don’t need to conform to industry standards’,” says Mr Marks. “There are two routes to influence: stand out, which is a hard messenger tactic, or fit in, which is a soft message. Zuckerberg’s clothes say ‘I’m a down-to-earth guy, very likeable, but also the CEO’.” The smart-casual trusty trio of tan chinos, loafers and a white, button-down Oxford shirt will help you straddle the line between corporate go-getter and approachable team member.

Your CEO, who eschews the company car in favour of a bicycle, is doing more than his bit for the planet. “Status hierarchies aren’t always formed on the basis of business success and wealth; we have them in all areas, including the idea of what makes a good, upstanding citizen,” says Mr Marks. “People have a desire to be seen as warm, social and good members of the community. Cycling is an eco-friendly, health-conscious act and is an activity people respect because it requires a level of fitness. You’re showing you are morally respectable and it’s a sign of superiority in a non-traditional way – you get reputational benefits through that.” Take up cycling, invest in full Café du Cycliste kit and make sure you parade across the office at 5.55pm for everyone to see.