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5 Ways to Decide Who You Can Trust

Before you commit, are you sure you're in your "wise mind"?

Key points

  • Trusting the wrong person can result in a variety of undesirable outcomes.
  • There is no evidence that "untrustworthy" facial features predict actual behavior.
  • To make better choices about who to trust, avoid impulse decisions and beware of people who move too fast in relationships.
Source: Stock-Asso/Shutterstock

One of the most important decisions you make in life is deciding who to trust. Trusting the wrong person can result in abusive relationships, date rape, being taken advantage of, financial losses, and many more undesirable outcomes.

It would be nice if the sociopaths who lurk among us actually looked suspicious, and if the psychopaths wore labels saying "Be scared—be very scared." Unfortunately, this is not the case.

In fact research shows that people with narcissistic personalities—who tend to manipulate other people for their own selfish ends—actually present as especially charming and attractive on first impression. They also are more likely to have high-status jobs or possessions. So how do you avoid the con man or serial seducer? Understanding your brain's automatic wiring may hold the key.

How Our Brains Judge Character from Facial Appearance

In 2003, Princeton researcher Alexander Todorov showed pairs of pictures to about a thousand people, then asked them to rate who was more competent. The participants did not know they were looking at actual candidates for the House and Senate in prior and upcoming elections. Across several studies, participants’ responses to the question of whether someone looked competent predicted actual election outcomes about 70 percent of the time (Read the study here). Even when people looked for just one second, predictions were more accurate than by chance!

A subsequent study showed that we make snap judgments about competence based on facial features denoting trustworthiness and dominance. These initial judgments color our perceptions about the individual from then on. The researchers found that the "most trustworthy" faces had upturned eyebrows and lips, while the "least trustworthy" faces had eyebrows pointing downwards and lips curled at the edges.

The Split-Second Judgment

In a more recent study, published in the Journal of Neuroscience in August 2014, researchers from Dartmouth and New York University showed that our brains take just three hundredths of a second, much less time than an eye blink, to decide trustworthiness. In fact, our judgments about trustworthiness are so rapid that we are able to make them even before we know who the person is!

The researchers showed people photos of both real faces and computer-generated faces deliberately designed to look either trustworthy or untrustworthy. Results showed that we judge people with high eyebrows and prominent cheekbones as trustworthy, while we distrust people with furrowed brows and sunken cheeks. There is no evidence that these characteristics actually make people more or less trustworthy in real life.

This rapid, automatic response likely served our ancestors well when they had to decide in the blink of an eye whether an approaching stranger was a potential ally or a marauding tribesman coming to kill them. While this rapid response may be helpful to us in certain situations, like walking alone in a dark alley at night, it may actually make our day-to-day reactions to people biased and inaccurate.

Remember, there is no evidence that these "untrustworthy" facial features predict actual behavior. These negative facial stereotypes are probably enhanced when we go to the movies and see villains with sunken cheeks and furrowed brows, like batman's arch-enemy, the Joker, so scarily portrayed by Jack Nicholson. And what about Hollywood's famous brow-shaper Anastasia, who made an empire out of trimming celebrities' brows to have precise, high arches?

The Role of the Amygdala

In a second part of their experiment, the Dartmouth and NYU researchers used an fMRI brain scanner to find out what part of the brain lights up when we make decisions about whether to trust somebody. Using a new group of participants, they flashed the faces on a screen for 30 milliseconds, followed by an irrelevant image, in a procedure known as "backwards masking." This made the brain unable to consciously process the facial features. Results show that our brains process faces and make judgments about trustworthiness even without conscious awareness. This activity occurs in the amygdala—a part of the limbic system that serves as our brain's alarm center. It judges whether something we see (or hear, smell, taste, or touch) is an immediate threat. If it detects a threat, the amygdala initiates a "fight-or-flight" response that releases a cascade of chemicals to ready our minds and bodies for escape or doing battle.

So it seems we can get into trouble if we follow our "gut feelings" about whom to trust. Our brains and guts are just reacting automatically based on superficial characteristics that don't predict actual character or behavior. Perhaps this is why so many innocent young women cheerfully walked off to help serial killer Ted Bundy put books in his car, without an inkling of whom they were really dealing with. Perhaps sunken cheekbones really did signal danger to our ancestors who lived in times of famine. Starving people who had more sunken cheekbones may have been more desperate for food and therefore more likely to harm you to get it. But in modern America, sunken cheekbones don't predict anything. So how do you protect yourself better from untrustworthy types?

How You Can Make Better Choices About Whom to Trust

  1. Step back and take time to think. Don't make important decisions on impulse, whether it's a major purchase, an investment, a change of jobs, joining a gym, or deciding to leave a party with a stranger. Better to go home and mull over the costs and benefits, or consult with a friend whose judgment you trust, before acting.
  2. Beware the hard sell. Many retailers (and lots of online coaches) know that your brain makes less accurate decisions on impulse. If we make decisions on the spot, we are more likely to be drawn in by a special deal or promise that sounds too good to be true. So beware of any offer that expires in the few next hours, or "one-day only" sales. Sellers will create the appearance of scarcity to lure you into making quick decisions. This means your amygdala decides, rather than your prefrontal cortex, which is designed to weigh choices based on rational factors and past experience.
  3. Beware of people who move too fast in relationships. If you just met a person and they want to be your best friend or the love of your life, be careful: At minimum, this person is probably impulsive and doesn't think things through before acting. They may be projecting a fantasy onto you, or be more into "intensity" than real intimacy when it comes to relationships. They may thrive on drama—then move on quickly when they get bored. At worst, they may be deliberately creating an appearance of intimacy to seduce you or lure you in. The wisest thing is to ask the person to back off a bit so you can take time to get to know them. Decide on your own limits ahead of time—and stick to them.
  4. Ask yourself what this person is really about. Some people are really good at projecting a confident, sexy, fun-loving spirit or making you feel really attractive and important. But if you take a step back, you may want to ask yourself: How well you actually know this person? And how much are they really into you? Do their eyes wander around the room, looking for their next conquest or to see who is admiring them? How do they treat people like the waitress or cab driver? If you listen carefully to what they say, what are the underlying values? Are they critical and contemptuous of others? Do they remember what you tell them? How considerate and thoughtful are they? Do they have close friends, or are they close to their family? Asking yourself these questions can help you move beyond superficial aspects of the person, to consider qualities that are more important in the long-run.
  5. Use your wise mind. Psychologist Marsha Linehan coined the concept of "wise mind" to describe a state of mind that integrates logical thinking with emotional awareness. It is a mindful state in which you make decisions by integrating different ways of knowing and don't cut off parts of your experience. If you feel an instant connection with somebody, take this into account, but don't make it the whole basis of your decision. In our wise mind, we don't ignore emotions, but we also don't get so caught up in them that we see only what we want to see, instead of what is actually there. In brain terms, wise mind means integrating our amygdala's intuitive reactions with the wisdom of past experience and knowledge about the world.

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