Thanks to a recent kerfuffle over the Earth’s precession and its effect on our astrological signs, many people have spent this week questioning their personality traits. I went from being a life-long Gemini (changeable, duplicitous) to a possible Taurus (stubborn, steady), neither of which I think describe me. I’ve never believed in astrological signs, but many people do, and this week must have been a confusing one for them.

The whole thing got me thinking about how we look outward for explanations and definitions of our inner selves. No one has a better vantage point than we do to observe our own personal thoughts, feelings, attitudes, and behaviors. How funny that we once looked to the stars in order to understand ourselves! Those of us who consider ourselves scientific and modern are no better. Although we scoff at sun signs and palm readings, increasingly we are turning to our brains and our DNA for answers that they simply can’t give.

In the 1800’s, the Phrenological Fowlers (later Fowlers and Wells) founded a nationwide industry on reading people’s personalities based on the bumps on their heads. They published extensively and sent emissaries to small towns throughout the U.S. so that, for a small fee, the masses might come to know themselves better. The company and its methods were an unrivaled success. America was obsessed with phrenology. Sometime in the 1860’s, a curious Mark Twain visited Fowler’s office under an assumed name. Fowler read his head and said that his skull dipped in at a particular point where it should have bulged out – a sure sign that Twain, the preeminent American humorist, utterly lacked a sense of humor.

Nowadays, many still look to their brains for answers. When I used to scan participants in fMRI experiments, they would often ask what I could tell them about their brains. I couldn’t tell them anything; all the analysis took place later, back at the lab. But as a frequent subject in pilot experiments for my own and colleagues’ studies, I’ve had unfettered access to data from my own brain. I know that I have a large and robust fusiform face area (a region thought to be critical for face recognition) and a rather dinky visual word form area (implicated in identifying letters of the alphabet.) What does that mean, when I am an avid reader and often embarrass myself with my poor ability to recognize faces?

While people still look to the stars and to brains (if not skulls) in order to understand themselves, the next big thing has arrived. The age of personal genomics is upon us and countless startups out there are eager to swap a check and a swab of our cells for a glimpse into our futures and ourselves. I have to admit, I fantasize sometimes about having my genome read. I would love the chance to pour through details about my ancestral line or learn what type of diseases I am predisposed to developing. But the biggest draw is to learn about myself. What forms of the anxiety genes do I have? What about genes linked to mental illness, intelligence, novelty-seeking? As a scientist, I know that complex traits are determined by a mixture of environment and numerous genes, many of which we haven’t yet discovered. Beyond that, epigenetic factors influence the expression of our genes in ways we don’t yet understand. Yet I still find myself wishing someone would hand me that printout with the secrets to myself.

The cognitive scientist Steven Pinker wrote a wonderful essay wading through his results when his own genome was sequenced. In it, he struggles with the discrepancies. His genome says he should be sensitive to bitter flavors, yet he enjoys beer, broccoli, and brussels sprouts. His genome says he has a high risk of baldness, yet he is known for his thick mane of overflowing, curly hair. Other results he believes or would like to believe. What is a person seeking direction and self-wisdom to do?

So at the end of this astrologically confusing week, I find myself at a loss. Why do we crave external guidance to help us understand our internal selves? It may be because we are less static and more changeable than we like to believe. As I alluded to in my post about our potential to do evil, psychology experiments (and history) have shown that human beings are heavily influenced by their circumstances. Because we are adaptable, we behave very differently depending on who we are with and what we are doing. Although the adaptability may be advantageous, I suspect it unsettles us. We want to believe we have a solid, stable identity, and we will look to mystics or scientists – anyone who can give us that assurance. I know who I am and who I always will be.

The hard (but in its own way beautiful) truth is that we are each a complex and contradictory landscape of traits, behaviors, and passions. Be wary of those who try to describe you with a handful of paltry adjectives. Know thyself. Or keep trying, anyway. It should take at least a lifetime.