Further to my comments to a fellow Tippling Philosopher, I emailed this the other day
Another thing I wanted to add was the idea that the mental, the experiential, supervenes on the physical. This means that the physical in some way defines and is necessary for the mental.
This is becoming more and more evident. Let me exemplify:
How much do you love your mother? Was this attachment, if you did, consciously chosen? This doesn’t happen by accident, but on purpose. Looking at mice and mice pups, we know that when we engineer mice pups to lack a particular receptor in the opioid system, the pup shows no preference for its own mother against any other mouse, letting out fewer cries at separation, all through chemical signalling. The same when they are presented with their mother’s nest and another. That is not to say they no longer care full stop, since they are more reactive then others to a threatening male mouse or to cold temperatures… Mice need to be correctly running the correct genetic programs in order to care about their mothers. And the same, it is claimed by some, is the case for autistic people with attachment disorders (with any kind of group correlation, there must be SOME kind of causality at play).
I would claim that the belief that human brains may operate in different ways than other mammalian brains is fine, though to deny that similar receptors would operate in an similar way would require a burden of proof.
Now let’s turn to faithfulness. And this might depress some of you. Monogamy and faithfulness to partners is a moral judgement which reflects our moral character right?
Well…. Some of you may remember the interesting research that came out about prairie voles. Generally speaking, these animals are monogamous, forming life pair-bonds in which they nest together, huddle up, groom and raise pups as a team. Why such commitment in this species and not others? Do they choose to be such?
Well, the answer lies in hormones. When a male vole repeatedly mates with a female, a hormone called vasopressin is released in the brain. This binds to receptors in the area of the brain called the nucleus accumbens. This process mediates a pleasurable feeling that becomes associated with that female. This locks in the monogamy, known as pair-bonding.
If you block this hormone, then the pair-bonding evaporates. Furthermore, if you raise those levels of vasopressin genetically in other species, they take on monogamy!
So, again, you might question whether this is applicable to humans. A 2008 Swedish study examined the receptor in 552 men in long-term heterosexual relationships. It was found that a section of the RS3 334 gene can come in a variety of numbers: no copies, one or two copies. The more copies, the weaker the effect of vasopressin on the brain. Such a simple thing can have profound effects, since the number correlated with pair-binding measures. Men with more copies scored less, including strength of their relationships, perceived marital problems, marital quality as perceived by their spouses etc. Those with two copies were more likely to be unmarried, and if they were married, to have marital issues.
Looking at evolutionary psychology, there has been work done on love and divorce. Apparently, when people fall in love, there is a period of up to 3 years where infatuation and zeal ride a peak. The love drug is in the signals sent in the body and brain. After this time, the signals begin to decline. It is proposed that we lose interest in a partner after the time required to raise a child has passed, which is, on average, about 4 years.
This would make sense in the context of other species such as foxes, who pair-bond during the breeding season, stick around to raise offspring, and then go their own ways. Results from divorce studies in 60 countries show that divorce peaks at around 4 years in line with such a hypothesis. The love drug’ gives us efficient and timely influence to stick around to produce offspring then to look elsewhere.
Obviously, with humans, we have become incredibly complex creatures, and there are many variables to mitigate this, but as a theory based on a good deal of research, it has some explanatory power.
The things is, free will, as a concept, has to be able to explain, to take into account, every single piece of correlation / causation evidence, every bit of social science which show that subsets and groups are more likely to do x rather than y.
The issue is that when you take the full plethora of these pieces of research, what is there left? A tiny percentage of human possibility for free will.
Incidentally, I have been I have been toying with the idea of collating all of the research which defends the lack of free will. A daunting task since there is so so much. To defend free will? Absolutely no empirical evidence whatsoever. None.
So when you are talking about explanatory power and scope, free will as a thesis cannot even get near to determinism. The only hurdle for determinism is the idea that we ‘feel’ like we have free will. And that is a cinch. After all, I feel a lot of things which are false (the world ain’t flat).