Do brain region sizes or pheromones prove homosexuality is genetic?


In college I've been taking a non-verbal communication class which teaches us about different aspects of what some people refer to as "body language". Throughout the class the instructor had made claims that homosexuality has a genetic basis and that there's evidence that may lead us to believe that people are born that way.

One evidence the teacher claims is that women are born with brains that have a larger "corpus callosum" (which connects the left and right hemispheres of the brain) than men, and homosexual men have a large corpus callosum too. This is supposed to say that women and gay men are more emotionally expressive.

Another piece of evidence we discussed in class was about pheromones relating to smell. In our textbook it talks about how women are sensitive to a male hormone pheromone called "androstenone", and that the sexual regions of their brains are activated by that pheromone. The book also goes on to state that homosexual men also respond to "androstenone", the same way women do. It also states that straight men and lesbian women's sexual region of the brain are activated by the smell of estrogen.

I'm curious to know what you think and how do you respond both scientifically and biblically to these claims of evidence, which my teacher implies that homosexuality may be genetic and people may be born with it?


The problem is that people have been searching for a genetic cause for homosexuality for decades and have yet to prove their case. Yet, because they are so certain that one must exist, they latch on to each possible hint and do not look at the evidence critically. I found the study on the pheromones. It notes a statistical difference in reaction in the section of the brain that is believed to be involved sexual arousal. They make no claim that it is genetically caused, in fact the cause isn't discussed. The reason is simple, people's sexual responses are trainable. So which came first, the scent leading to arousal or past arousals causing a sexual response because of familiarity? Thus this study does not prove nor disprove homosexuality is genetic, it only indicates that people respond sexually to scents they associate with sex, even if they are not aware of the particular scent.

The argument based on the corpus callosum, a region of the brain, is an even weaker argument because this particular study hasn't been reproduced. The typical approach to studies is to come up with an idea, study samples to see if there is support, and then publish your findings. Other scientists then take your idea and see if it can be replicated.

"There has also been speculation that part of the corpus callosum in male homosexuals is more like that found in the female brain than in the heterosexual male brain. (The corpus callosum is the largest cable of fibers connecting the two sides of the brain, ...). There have been twenty-three studies on the corpus callosum yielding conflicting results. Although the initial study found that the splenium of the corpus callosum was larger and more bulbous in women than in men, none of the other twenty-two studies was able to reproduce the sex difference in size. Some researchers found the splenium more bulbous in men, others in women, and still others found no sex difference. But some of the negative studies were misinterpreted as successful replications. Such conflicting results for gender make nonsense of any attempts to claim male homosexual brains are more like female brains."
[My Genes Made Me Do It - A Scientific Look at Sexual Orientation by Dr Neil Whitehead and Briar Whitehead]

In other words, the subsequent studies could not uphold that there is a sex difference in the corpus callosum between men and women let alone between homosexual and heterosexual people. Since this subsequent evidence was not produced in your textbook and your instructor did not bring it up, it is clear that facts are not important in this class. Your instructor is only interested in promoting an agenda, which is to make homosexuality to appear to be acceptable.

Even if a size difference is found in an area of the brain (which has failed so far), science still must wrestle with the problem of cause and effect. One scientist, named LeVay, thought he found a difference in a region labeled INAH-3. Subsequent studies also showed that his idea was not replicable. In addition, severe flaws were found in his original study which invalidated his conclusion.

"Although he originally commented about his findings: “It’s one more nail in the coffin of critics who argue that homosexuality is a choice and thus immoral,” when he is pressed, LeVay is more moderate. He says “the results do not allow one to decide if the size of the INAH-3 in an individual is the cause or consequence of that individual’s sexual orientation.” In other words, homosexual behavior could have created the difference.

"The human brain changes at the micro-level in response to the way we live: in response to learning, to the way we behave, and to all sorts of habitual stimulation. ...

"We change our brains at the micro-level through the way we exercise, and anything we do repetitively especially if associated with pleasure (e.g.) sexual activity. So, if LeVay did find real differences in the brains of his subjects, it is quite possible they were the result of homosexual activity.
[My Genes Made Me Do It - A Scientific Look at Sexual Orientation by Dr Neil Whitehead and Briar Whitehead]

Actually, the claim that your teacher is making borders on the ridiculous. If I wanted to get to know you, would it help if you sent me a sample of your genetic material? I could send it down to the lab and have a report back that told me all about how you behave in different situations. Silly, right? We all know that our genes do not dictate our behavior, though many people wish that were true. Even if we could claim that genes gives us a tendency to respond in certain ways, we know that we can act in spite of our instinctive response. For instance, I jump at sudden loud noises, such as a gun shot nearby, but soldiers don't. Their instincts are no different than mine, but they received training to ignore the compulsion so they can focus on their task. Thus we can't tell anything about how people behave based on their genes -- and that would include homosexuality.

When we add in what the Bible teaches, that homosexuality is a sin (I Corinthians 6:9), it is clear that God says homosexuality is a choice. "No temptation has overtaken you except such as is common to man; but God is faithful, who will not allow you to be tempted beyond what you are able, but with the temptation will also make the way of escape, that you may be able to bear it" (I Corinthians 10:13). No one is forced to steal, to lie, to commit fornication or homosexual acts; they are each the result of a choices an individual makes. "Whoever commits sin also commits lawlessness, and sin is lawlessness" (I John 3:4).

To claim a homosexual has no choice in whether to act against God's law or not is to claim that God made him sin. This is really what people are aiming for. By pushing the blame of their sins onto God one of two things is possible: First, they can claim God causes sin, which contradicts the Bible. "Let no one say when he is tempted, "I am tempted by God"; for God cannot be tempted by evil, nor does He Himself tempt anyone" (James 1:13). Second, they can claim that the Bible is not relevant and thus can be ignored because of supposed inaccuracies. You see this in denominations who vote on what laws of God they will or will not follow. In short, it is just a form of rebellion against God.