9 predictors of success in life that are almost entirely out of your control

Your facial structure

A 2015 study found that people whose faces convey the impression of trustworthiness and dominance may earn higher salaries.

For example, participants awarded hypothetical candidates for a head of retail operations position an extra $419 when the candidates looked trustworthy and an extra $355 when the candidates looked dominant.

Looking trustworthy and/or dominant is based mostly on your facial structure. Studies have found that dominance is associated with "masculine" features, like a squared face, strong jawline, pronounced eyebrows, and thin eyes and lips. Trustworthiness is associated with "feminine" features like a round face, big eyes, small eyebrows, and full lips.

In other words, barring cosmetic surgery, you've got minimal control over how trustworthy or dominant you appear.

Your accent

It's not just what you say in a job interview, but also how you say it that determines whether you get hired.

Research suggests that some employers may discriminate against candidates for executive positions when the candidates have foreign accents. That's likely because the employers may believe that those candidates have less political skill.

The researchers behind the study say companies should add accent-bias awareness training to existing training programs for hiring managers, in order to help reduce this unfair discrimination.

Scott Gries/Getty

Your natural body odor

Your ability to land — and keep — the person of your dreams depends a lot on your personal scent. Scientists say we seek mates who are neither too similar nor different genetically — and we make those judgments based partly on body odor.

In a 2006 study, for example, researchers recruited heterosexual couples to answer questions like how much they were turned on by their partners and how many other people they'd had sex with during the course of the relationship.

Meanwhile, the researchers took DNA from the participants' mouths as well as their partners' and brought it to the lab for testing. Specifically, they wanted to compare their major histocompatibility complexes, which are immune-system genes.

The researchers found that the more similar their MHCs were, the less attracted the participants were to their partners and the more likely they were to have had sex outside the relationship.

At the same time, studies have also found that we avoid partners who smell too different from us.

Your voice

We make a lot of judgments about people's professional capabilities based on their speaking style.

For example, a growing body of research suggests that deeper-voiced political candidates are more likely to win US elections. That's likely because we perceive them as stronger and more competent. Men and women with lower-pitched voices usually have higher levels of the hormone testosterone, meaning they're stronger and more aggressive. 

And even though physical strength isn't a reasonable requirement for today's presidents, our preference for leaders who can fend off a lion attack could be a relic of our caveman days. 

Similarly, one study found that deeper-voiced male CEOs lead larger firms and, consequently, are paid more. A 1% decrease in a CEO's voice pitch is linked to a $30 million increase in the size of his company. (The study authors admit that they can't prove having a deep voice causes people to see you as CEO material, but they think it's likely.)

Your parents' educational background and career

A growing body of research suggests that Mom and Dad's success meaningfully affects yours.

For example, as Business Insider's Rachel Gillett reported, one study found that parents' education level when their kid is eight years old predicts the kid's achievements 40 years later. That could be partly because the children of more highly educated parents set greater career- and academic-related expectations for themselves.

Meanwhile, more recent research found that daughters of working mothers earned a whopping 23% more than daughters of stay-at-home mothers. Sons of working mothers spent more time on household chores and childcare.

Peter Macdiarmid/Getty

Your height

It's still unclear why, but tall people seem to have a significant advantage over their shorter counterparts. 

One 2004 study found that the taller you are, the more you earn. In fact, according to that study, a person who is 6 feet tall would be predicted to earn nearly $166,000 more over the course of a 30-year career than someone who clocks in at 5 feet 5 inches. (The researchers observed those results even when they controlled for gender.)

Perhaps even more importantly, recent research found that taller people are more satisfied with work and with life in general. 

Your birth order

Scientists have observed that first-born kids tend to grow up to be more successful; they do better academically and are more likely to hold leadership positions as adults.

Why that's true is still anybody's guess. One recent study found that there are negligible personality and intelligence differences between firstborns and little sibs.

Another possibility, put forth in a 2013 paper, is that parents are more strict with their first kids than with the other ones, which could explain why eldest children wind up more accomplished.

Meanwhile, one psychologist told Business Insider that only children tend to turn out much like firstborns, in terms of intellectual ability and success, since they get their parents' undivided attention.

The month when you were born

Call it the "relative-age effect" or the "birth-date effect": Kids born closer to the cutoff for starting school or sports tend to be at a meaningful disadvantage.

In fact, one study found that there are surprisingly few CEOs born in June and July. That's presumably because the June and July babies were younger than everyone else in their grades, meaning they started off behind intellectually.

Flickr/Luca Boldrini

The weather during your job interview

The forces of nature may play a hand in your career — sometimes for the better and sometimes for the worse.

Researchers looked at data on nearly 3,000 medical school applicants and found that those who interviewed on rainy days received about a 1% lower score than those who interviewed on sunny days. Even senior interviewers were susceptible to this apparent bias.

The study authors write: "The difference in scores was equivalent to about a 10% lower total mark on the Medical College Admission Test."