Philosophy of Genetics

The problem with Heritability

Heritability is defined as the proportion of variation between two people that is explained by their genetic differences.  If the variation in height between identical twins (who have identical genes) is 2 inches, this is 0% heritable, because it's not based on genetic differences (there are none).  It must be explained by differences in their environment, right?

Perhaps.  But I can think of other examples where this breaks down.  If a gene (or something the gene constructs, like the motivational center of the brain) is designed to be triggered by a very specific environmental condition, that condition is implicit in the gene itself.  (See also, for example, my tale of the elevator).

Here are a couple of examples of "theoretical genes" where, by definition, the differences are 0% heritable (i.e. 100% based on experience), but you certainly wouldn't say they were not genetic:

• Niche differentiating genes
• Scenario differentiating genes

Niche differentiating genes

Teenagers are always trying to find their own unique niche, so they can be a little bit different from their friends. So imagine two robots that are built identically, with the same built-in programming, and imagine also that they both have the same program to observe the other robot and avoid duplicating the other’s behavior. When one lifts its arm, the other (after observing this action) lifts its leg instead. When one goes outside, the other stays inside. When one rolls its eyes, the other one sneezes, just to be different.

So in each case, the environment (observations of the other robot) leads the behavior of each robot to diverge from the other, yet they both contain the same program (identical "genes"). Carried to an extreme, if one robot sees its peer go to college, it may instead “choose” to skip college and enter the job market immediately. However, the (innate) desire to carve its own niche may be in competition with its (innate) desire to seek achievement (this conflict may cause the robot some stress!)

Part of anyone’s environment is the choices made by other genetic beings. So it’s difficult to truly assess how much of an effect the non-genetic environment has on an individual.

Scenario differentiating genes

The MAOA gene comes in multiple variants. Individuals having the AH variant of the gene are optimistic and resilient to bad treatment (in other words, they bounce back quickly after being treated badly).  Individuals with the AL variant, on the other hand, react strongly to maltreatment, and often develop antisocial behavior in response to it.

So imagine two identical twins, both with the AL variant of the MAOA gene. Imagine that these twins were separated at birth - one was adopted by a loving family (FL), and the other was adopted by an abusive family (FA). Clearly, the one raised in the abusive family would have a greater chance of becoming antisocial.

Although the ability to recognize abusive scenarios is shared in the twins (since how could a gene have any effect unless it recognizes the various scenarios for which it is designed to be affected?), only one individual received this environment. Yet both twins have the same innate branching circuitry. If situation A, then outcome B. If situation C, then outcome D.

So just because the outcomes are different does not mean that the behavior is not 100% genetic.

(Note, the full name of what I called the "AL variant" is "MAOA promoter polymorphism, low-activity".  I just think all those scientific terms get in the way of understanding the philosophical implications!)

Parents provide their children with Genes

Steven Pinker writes in The Blank Slate that “[p]arents … provide their children with genes, not just a home environment” (p. ix).  Therefore, all studies showing that “[l]oving parents have confident children [, and] authoritative parents…have well-behaved children” need to be “redone with adopted children (who only get their environment, not their genes, from their parents)”.  Only then will we know whether good nurturing really makes a difference.

It seems common sense to most people that parents’ nurturing skills are what influence their children’s success.  But common sense is often wrong.  Common sense tells us that if we travel in a car moving at 0.5c and we throw a ball ahead of us at 0.5c, then the ball will be traveling at a cumulative speed of 0.5c + 0.5c = 1.0c.  But as Einstein showed, this is wrong. 

When we study human nature, especially, we need to be wary of our own common sense, for it will mislead us.  Pinker points out (p.43) that we humans tend to confabulate, or make up plausible explanations for things.  When the human brain studies itself, the observer tends to get in the way of the observed.

So whether we believe it or not, studies show that "[v]irtually all the differences in parenting within a family can be explained as reactions to genetic differences that the children were born with" (p.389).

Thanks for the Memory

Slate magazine recently published a couple of stories about the arrival of new memory drugs and memory enhancement techniques.  These will be godsends for an aging populace suffering from mild cognitive impairment.

What is probably more interesting is why we remember what we do.  Certainly we remember what interests us (and excites us, motivates us, drives us, etc), and we forget what doesn't.

The amygdala (in the center of the brain) helps to process and categorize our experiences.  Is the structure of the amygdala different among the population, leading boys to be more interested in trains and girls more interested in dolls?  Is it responsible for causing some to be interested in seeking power, whereas others are only interested in seeking approval?

What's the value of an Idea?

What’s the value of an idea? If someone creates a better mousetrap, how much of a premium can they charge for it? If someone develops an entirely new process (for example, the first caveman to invent a reliable means to start a fire), what’s the value of that process?

We can learn from Economics. Certainly entrepreneurs are constantly trying to devise new products and processes that replace the old ones.  Joseph Schumpeter called this “creative destruction”. Desirable products can be sold for higher prices, and this is how the entrepreneur makes a profit.  Such products and processes can enhance our productivity. The invention of fire made human life better in many ways. The same with the invention of the light bulb, the computer, the automobile…

So is the value of an idea measurable by its price in the marketplace? Certainly the value of an idea decreases over time, as it is increasingly commoditized, and replaced by other ideas. A new and innovative drug, for example, will become less desirable over time, as alternative treatments (with fewer side-effects) are discovered by other entrepreneurs.

The invention of fire was a revolution in its day.  Prior to that, many people spent their lives trying to uncover its secret (or eating raw meat). Perhaps the person who first discovered fire was paid a rich reward in prestige, power, animals, land and a prized mate. But once the secret was discovered, it was easily conveyed to others in an afternoon’s training session, with the trainers receiving only a minimum wage.

The value of an idea is time-dependent. Imagine if people in the 19^th century woke up one morning and discovered a laptop computer in their office.  Would they even be able to maintain it, charge its batteries, understand it, support it?  What sort of energy would it take to propel such ideas backward in time?

Economics can provide valuable lessons for understanding the process of evolution and intelligent design. Each evolved component of a human being - ability to acquire language, ability to see and hear, etc - is a discovery.  (A catalyst is the most basic idea of all - an idea manifest in the very shape of matter).  Perhaps the process of evolution has its investment bankers, willing to risk capital on a new idea in our form. Perhaps genetic ideas are granted “patents” to protect them from “price competition” for a period of time. Perhaps there is an innate currency used by the process of evolutionto reward winning ideas.

Can anyone become President?

Fred: So why aren't you running for President?
Joe:  I could if I wanted to.  I'm just not really motivated, that's all.
Fred: Why don't you motivate yourself?  Buy an inspirational book.
Joe:  Maybe it's my mood, or maybe my willpower is not strong enough.
Fred: Anybody can do what they put their mind to...
Joe:  Hey, I made a choice, of my own free will.  I decided not to run for President, OK?  I just don't want to.  It's my choice.

People often separate their "wants" (what they perceive as their free choices) from their underlying motivations, moods, and -- ultimately -- genes.  They believe they have a free choice to do anything, and that they can summon the willpower and motivations to support any freely made decision.

But this is the major confusion with the notion of free will.  The "wants" that guide our choices are based on our motivations and moods and desires, which are innate (since how would you teach someone to crave leadership?).  Because our moods and motivations change over time and situation, we don't think of them as being a permanent part of us.  We think they are something that "happens" to us.

And, in the same way, the desire to be a follower is also innate.  Followers are easily excited by a charismatic leader, who smiles at them and gives them praise.  Do followers freely choose to get excited, or is it something that happens naturally (for some people)?  Then, when they "want" to follow that leader, is it a free choice?  Or a choice based on their mood?

Does everyone have the same mood when they listen to a charismatic speaker?  Can everyone become a charismatic leader?  No.  A charismatic can smile in the face of disapproval.  Many people are simply not able to smile in that situation - they feel uncomfortable, and cannot bring themselves to smile.  The charismatic can confidently make statements about how the world should be.  Other people are highly motivated when someone is speaking confidently to them, and they are willing followers.

Kant: We only sense things for which we were built

As Kant wrote, we only sense things for which we were built.  In other words, for something in the environment to affect us, our brain must be constructed (by our genes) to be affected by that stimulation.

Like my story of the elevator - which is built to be affected by pressing its buttons, but not by loud noises - humans have a series of instincts, reactions, behaviors, motivations, emotions, fears and drives, which are triggered by environmental situations for which they were built to be triggered.

Thomas Hobbes wrote that talents are equally distributed.  But many recent studies have shown that we have a great deal of genetic diversity.  We are innately affected by many aspects of the environment. Having more instincts gives us less free will, not more, since there more things in the environment to distract us.

Genetic differences among women

"Literally every one of the females we looked at had a different genetic story," said Duke University genetics expert Huntington Willard, who co-wrote a recent study. "It is not just a little bit of variation."

The study showed that "activity level varied widely by woman, from zero in some  to varying levels in others" on their X chromosomes.  (Women and men both have the X chromosome, although women have two X copies and men have only one X and one Y).

According to a news article, "the analysis also found that the obsessively debated differences between men and women are, at least on the genetic level, even greater than previously thought ... As many as 300 of the genes on the X chromosome may be activated differently among women than among men, said molecular biologist Laura Carrel at Penn State University, the other author of the paper."

What is Truth? or, are Lawyers the ideal life form?

Truth emerges between motivated antagonists, like lawyers in a courtroom who passionately put forward the most favorable arguments and facts for their side of a case.  Any one person is always biased and partisan, never objective.

So it follows that two lawyers (in opposition) can expose the truth behind an issue, as long as they are sharp, eloquent, with a good mind for facts, and highly analytical.

If, one day, people could choose the genes to be more lawyer-like (intelligent, motivated by intellectual battles, well-spoken, able to defer gratification during long years in law school), would the world be a better place?  Certainly there would be a greater diversity of ideas (although less genetic diversity).  Would we have more truth?

The Math Myth?

Time Magazine recently published an article on "The Math Myth", asking whether "men are better equipped for scientific genius" than women.  But I think the question is misleading for the following reasons:

Geniuses are a breed apart.  They are like an irrepressible force of nature.  They will work obsessively on problem-solving from morning to night.  They don't need additional motivation.  They don't care what society says.  They don't need approval or validation or recognition.  A genius needs to maintain such a level of focus, to discover something entirely new for mankind, especially in the face of criticism and ridicule by luddites.  In my experience, this type of anti-social behavior is much more common in men. 

Even if women and men have the same raw talent for math and science, they may have other competing motivations, such as a feeling of obligation toward others like parents and children.  Many women speak of things like "society tells us to do XYZ" and "women are not encouraged to do XYZ".  But why care about what society thinks, unless you are motivated (from within) to listen to those words.  From an early age, boys (such as my son) are clearly more interested in physical objects than in "doing what society encourages".

According to Time, "Boys and men are still on average better at rotating 3-D objects in their minds".  Women's spatial reasoning improves "after spending a couple of hours a week...playing Tetris".  So the real key to gender difference may not lay in the part of the brain that controls spatial reasoning -- it's in the part of the brain that makes boys obsessed with certain behaviors like playing Tetris!  (That indirect link doesn't make it any less innate, though).

If you have the talent to be a genius, but you don't feel like applying it (for whatever reason) it has the same effect as if you didn't have the talent to begin with. The outcome is the same.

Tuning & Expectation

When we are born, our eyes are not fully developed.  We need to see the world in order to "fine-tune" our vision.  We need to be exposed to horizontal lines, vertical lines, various shapes...   Babies have a natural instinct to keenly observe the pattern in front of them when they are being held, and that pattern is nearly always a face!

Once the genes tune a part of the brain to recognize faces, the genes can then build other circuitry that depends on it... such as being cowed by a frown pattern, or being excited by a smile pattern.

So the genes don't have to specify everything in our mind, for those things to be innate.  The genes can make certain assumptions about the environment, like a plant can make assumptions about its environment (the sun will rise, wiggling will usually help it get around obstacles, it will rain occasionally).  Anything that's reasonable to expect in the environment is reasonable to be left out of the genes.

A young child who has one eye (but not both) closed for an extended period will have permanent problems with their vision.  But it's reasonable to expect that this situation will not usually occur.

Someone with innate leadership ability simply has a cluster of motivations and emotions.  They need to be tuned, in order for that person to be an affective leader.  They are the basic building blocks for leadership.  Some people don't have those basic building blocks, and so will not desire to become a leader ("I chose not to be a leader of my own free will," they may say) or will not have the ability to become a leader.

In order to develop leaders, first you need to assemble a group of people with the leadership genes.  You don't develop leader's basic motivations and emotions... you tune the people who are already leaders.