Whatever the actual cause for this anterior hippocampal enlargement, for a neuroscientist it’s actually quite cool to see something as complex and subtle as a personality trait potentially reflected by visible physical differences in the brain. It doesn’t happen nearly as often as the media implies.
Overall, some people actually enjoy the experience of encountering something that causes fear. The fight-or-flight response triggered by this leads to a wealth of heightened experiences occurring in the brain (and the palpable relief that occurs when it ends), and this can be exploited for entertainment purposes within certain parameters. Some people may have subtle differences in brain structure or function that cause them to seek out these intense risk-and fear-related sensations, to sometimes alarming extents. But that’s nothing to pass judgement on; once you get past the overall structural consistencies, everyone’s brain is different, and those differences are nothing to be afraid of, even if you do enjoy being afraid of things.
You look great—it’s nice when people don’t worry about their weight
(Why criticism is more powerful than praise)
“Sticks and stones will break my bones, but names will never hurt me.” This claim doesn’t really stand up to much scrutiny, does it? Firstly, the hurt caused by a broken bone is obviously quite extreme, so shouldn’t be used as a casual baseline for pain. Secondly, if names and insults genuinely don’t hurt at all, why does this saying even exist? There’s no similar saying to point out that, “Knives and blades will slash you up but marshmallows are pretty harmless.” Praise is very nice but, let’s be honest, criticism stings.
Taken at face value, the title of this section is a compliment. If anything, it’s actually two compliments, as it flatters both appearance and attitude. But it is unlikely that the person it’s directed at will interpret it as such. The criticism is subtle and requires some working out, as it is mostly implied. Despite this, it is the criticism that becomes the stronger element. This is just one of countless examples of a phenomenon that arises from the workings of our brains; criticism typically carries more weight than praise.
If you’ve ever had a new haircut or outfit or told a funny story to a group or anything else like this, it doesn’t matter how many people praise your look or laugh at your jokes, it’s the ones who hesitate before saying something nice or roll their eyes wearily at you that will stick with you and make you feel bad.
What’s happening here? If it’s so unpleasant, why do our brains take criticism so seriously? Is there an actual neurological mechanism for it? Or is it just some morbid psychological fascination with unpleasantness, like the bizarre urge to pick at a scab or poke a loose tooth? There is, of course, more than one possible answer.
To the brain, bad things are typically more potent than good things.34 At the very fundamental neurological level, the potency of criticism may be due to the action of the hormone cortisol. Cortisol is released by the brain in response to stressful events; it is one of the chemical triggers of the fight-or-flight response, and is widely regarded as the cause of all the issues brought about by constant stress. Its release is controlled mainly by the hypothalamic–pituitary–adrenal (HPA) axis, which is a complex connection of neurological and endocrine (meaning hormone-regulating) areas of the brain and body that coordinate the general response to stress. It was previously believed that the HPA axis was activated in response to a stressful event of any sort, such as a sudden loud noise. But later research found it was a bit more selective than that and was activated only under certain conditions. One theory today is that the HPA axis is activated only when a “goal” is threatened.35 For example, if you’re walking along and some bird droppings land on you, that’s annoying and arguably harmful for hygiene reasons, but it’s unlikely to activate the HPA mediated response because “not being soiled by an errant bird” wasn’t really a conscious goal of yours. But if the same bird were to target you while you’re walking to a very important job interview, then it is very likely to trigger the HPA response, because you had a definite goal: go to the job interview, impress them, get the job. And now it’s been largely thwarted. There are many schools of thought about what to wear to a job interview, but “a generous layer of avian digestion by-product” doesn’t feature in any of them.
The most obvious “goal” is self-preservation, so if your goal is to stay alive and something occurs that might interfere with your goal by stopping you being alive, the HPA axis would activate the stress response. This is part of the reason it was believed the HPA axis responded to anything, because humans can and do see threats to the self everywhere.
However, humans are complex, and one result of this is they rely on the opinions and feedback of other humans to a considerable degree. The social self-preservation theory states that humans have a deep-rooted motivation to preserve their social standing (to continue being liked by the people whose approval they value). This gives rise to social-evaluative threat. Specifically, anything that threatens someone’s perceived social standing or image interferes with the goal of being liked, and therefore activates the HPA axis, releasing cortisol in the system.
Criticisms, insults, rejections, mockery, these attack and potentially damage our sense of self-worth, especially if done publicly, which interferes with our goal of being liked and accepted. The stress this causes releases cortisol, which has numerous physiological effects (such as increasing release of glucose), but also has direct effects on our brain. We are aware of how the fight-or-flight response heightens our focus and makes our memories more vivid and prominent. Cortisol, along with other hormones released, potentially causes this to happen (to varying degrees) when we’re criticized; it makes us experience an actual physical reaction that sensitizes us and emphasizes the memory of the event. This whole chapter is based on the brain’s tendency to go overboard when looking for threats, and there’s no real reason why this wouldn’t include criticism. And when something negative happens and we experience it first hand, producing all the relevant emotions and sensations, the hippocampus and amygdala processes spark into life again, and end up emotionally enhancing the memory and storing it more prominently.