It’s a well-established fact that size influences our choice of leaders.

For example, CEOs of Fortune 500 companies are disproportionately over 6 feet tall. Similarly, the height of presidential candidates can partially predict the outcome of an election. Since the start of the 20th century, over 70% of US elections between the two parties have been won by the taller candidate.

Despite robust empirical evidence demonstrating our fondness of tall leaders, there isn’t as much known about the impact of leader’s weight on our leadership preferences.

To broaden this body of knowledge, Kevin Kniffin and his colleagues Vicki Bogan and David Just have recently published a paper in the journal PLOS One, that explores the impact of leader’s weight on their persuasiveness.

Big Man Ting

Anthropologists who have lived with hunter-gatherer tribes are very familiar with leaders being referred to as ‘Big Men’.

In addition to being influential and persuasive, leaders of pre-industrial societies also have to be physically formidable. Indeed, recent expeditions with hunter-gatherer tribes have found that physical size is associated with leadership— but primarily among men.

There are several reasons why this is the case, including the importance placed on fighting ability. Across the natural world, animals that are the most powerful and menacing fighters are generally granted high status (if you’re sceptical, watch one of David Attenborough’s latest documentaries). The same is partially true for humans too.

However, Kevin and his colleagues argue that overindulgence is a marker of social status and wealth within traditional communities (if people are struggling to eat and you’re actually fat, you’ve got to be doing something right).

The anthropological literature is replete with references to high status ‘Big Men’. However, you don’t need to unearth yellowing anthropology books to discover this association between size and status. A quick search of popular rap songs on YouTube provides you with lyrics like:

Yo, BMT, I’m on a big man ting
I ain’t going into clubs without my big hand ting
Got eleven on my finger, that’s a big man ring
Yeah I got a big bag, no bin man ting

In our post-industrial age of abundance, being overweight is increasingly linked with negative life outcomes— including diabetes and cancer. Indeed, obesity is now a bigger killer than hunger worldwide, and people who carry extra pounds find themselves subject to stigma.

Despite our newfound infatuation with thinness, Kevin and his colleagues wondered if this association between weight and social status still lingers in the modern world (beyond the UK rap community of course).

To explore this relationship, Kevin’s research team conducted a series of studies. Specifically, they wanted to see if overweight men are perceived as more persuasive than their scrawny counterparts.

As stated by the authors:

We focus specifically on persuasiveness since “big men” in pre-industrial societies did not have the power of an institution to enforce their standing in the group’s hierarchy; instead, “big men” needed to rely upon influence and persuasiveness to gain and maintain their status.

Heavyweight titans

As a preliminary step, Kevin’s team simply asked a small group of American university students to associate words with the phrases ‘heavyweight’ or ‘lightweight’.

Lo and behold, the students associated ‘heavyweight’ with strength, whereas ‘lightweight’ conjured negative connotations— such as being ‘weak’ or ‘unqualified’ (can you recall lightweight ever being intended as a compliment?).

The researchers commented that ‘heavyweight’ and ‘lightweight’ are terms commonly associated with boxing, and that heavyweight champions – the likes of Muhammad Ali and Mike Tyson—have garnered greater interest than lighter fighters (that is, boxers who are on their Big Man Ting).

When officially starting their research, Kevin’s team returned to their respective universities and asked students to evaluate their own leadership capabilities—including their ability to persuade others—and to disclose their height and weight (I know, how rude).

The researchers found that the students who rated themselves as more persuasive actually weighed more. Having dug into the data however, this relationship was largely explained by their height—rather than their weight per se. Therefore, these results weren’t entirely in line with their predictions.

Next, Kevin’s team sent out a survey to American undergraduate students. Specifically, the students were asked how persuasive they find people of different weights generally.

The most favourable answer received was that heavy people are more likely to be perceived as persuasive. In other words, the students stated they didn’t find overweight people more persuasive themselves— but believed that other people do.

In the later rounds of the research, Kevin’s team used drawings of men and women of different physiques. They asked American undergraduates to rate each of these figures on how persuasive, extraverted, funny and attractive they thought each person would be if they actually existed in real life.

The researchers found that the overweight male figures were rated as more persuasive—whilst the same wasn’t true for the female figures. In other words, there was no linear relationship between female figures’ weight and how persuasive students thought they would be.

They then repeated this drawing exercise with a broader American sample and people from Kenya. This was to make sure that these findings actually replicate, and are not just quirks of WEIRD people (that is, people who are Western, Educated, Industrialised and Democratic).

In both replications, they found that the overweight male figures were rated as more persuasive than the normal or underweight companions.

Fish out of water

Before delving any further, we first need to acknowledge the limitations of this study.

You don’t need a degree in psychology to realise that the researchers didn’t directly measure how persuasive individuals are among groups, but rather inferred influence through people’s perceptions. To be sure that this effect is real though, experiments would need to be conducted that directly measure the impact of people’s height and weight on their ability to influence (a tall order, I know).

Other scientific papers have recently been published that point in the same direction however, which lend further weight to these findings (no pun intended).

Future research should explore whether these associations are universal across cultures or dependent on context, as there are likely to be several exceptions.

As stated by the authors:

With further research, we may find out that the influence of weight on status and persuasiveness is context specific and culturally defined. Indeed, criticisms that a President of the United States would substantially under-report his own weight while perhaps over-estimating his own height are interesting in light of the studies we present.

Likewise, I suspect differences in body composition dramatically change how leaders are perceived (as the Body Mass Index doesn’t distinguish fat from muscle).

These points aside, how can we ultimately make sense of their studies’ results? Kevin and his colleagues interpret this phenomenon as an evolutionary mismatch.

To elaborate, evolutionary mismatches are physical and psychological traits that were selected for in our ancestral past, that are now frequently misaligned with the demands of the modern world (think of newly hatched sea turtles who are perilously drawn to streetlights).

Kevin and his colleagues argue that a proclivity for ‘Big Men’ constitutes an evolutionary mismatch, as there is no longer good reason to associate size with status. As we don’t have to hunt or worry about being raided by rival tribes anymore, the size of a leader is essentially irrelevant in the modern world of work.

The authors write:

As with studies of height in relation to non-manual work environments (e.g., being President of the United States), there is no essential relationship that should exist for weight. With the exception of certain athletic occupations such as sumo wrestlers or linemen on professional football teams, there is no clear rationale or consensus for why weight should be relevant for many contemporary occupations.

Implications

Clearly, this paper has several practical implications for the business world. As Kevin and his colleagues suggest, employers should be particularly sensitive to the various ways in which weight can cloud our judgement when it comes to hiring and promotion decisions. Businesses need to make a concerted effort to eliminate such biases during the selection process, and to focus on core competencies that underpin the role in question.

Perhaps most importantly, these findings have significant implications for democracies.

Against the backdrop of increasing political polarisation, prominent politicians are now placing greater emphasis on their size and fighting prowess (or rather, telling tales of their fighting history). Indeed, combative behaviour and threat displays have become unusually coarse among Western politicians— particularly in the United States.

Whether it’s ‘little Marco’ or ‘mini Mike’, President Trump continues to mock his political rivals based on their stature— which so far has proven to be a winning strategy. Beyond basic health considerations however, candidate’s size should be irrelevant when it comes to electing the President of the United States (note the irony of Michael Bloomberg’s latest campaign ads appearing to mock Trump based on his weight).

Across several spheres of society, being aware of these remnants of our primate lineage would likely benefit us. Armed with this knowledge, we can ultimately discard candidates’ size when selecting our leaders.

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Written by Max Beilby for Darwinian Business