My genes made me do it!

‘Infidelity genes’ discovered?


6 December 2004

‘The devil made me do it.’ That age-old excuse for sin, a way to deny personal responsibility for one’s actions, is no longer fashionable. As I wrote in a Creation magazine editorial ‘Evolution made me do it!’ in June 2000, nowadays, whether it’s homosexual acts, infidelity or whatever, it’s become, ‘My genes made me do it.’

And, because the blind forces of evolution are supposed to be responsible for shaping our genes, that rapidly translates as, ‘Evolution made me do it’. Thus the title of the abovementioned editorial, which pointed to a Time magazine cover story that proclaimed ‘Infidelity? It’s in your genes’.

Now, Professor Tim Spector, of St Thomas’ Hospital, London, has announced that studies on female twins have strongly suggested a genetic link to infidelity, involving certain areas of the chromosomes.1 In other words, a tendency to being unfaithful appears to follow a pattern of inheritance. (Twin studies are normally used to try to ‘filter out’ the effects of upbringing in such surveys. Identical twins separated at birth will have the same genes, but different upbringing.) How a person was brought up seems to be linked to their moral attitudes as to whether infidelity was wrong, but those attitudes are not correlated well with the behavior itself. According to Spector, who is director of the hospital’s Twin Research Unit, the study showed that if people were genetically predisposed to infidelity, they would on average exhibit a higher rate of infidelity, even though they might well strongly believe that it was wrong.

Whether this study will be confirmed or not remains to be seen. The fruitless and chequered search, punctuated by several false starts, for a ‘gay gene’, and a gene for alcoholism, and now a ‘God gene’ has not engendered confidence in this whole approach (maybe there’s also a gene that makes evolutionists believe that all beliefs are determined by genes). But, as we have pointed out repeatedly, even if such predisposing genetic factors for behaviour were to ever be confirmed, it would be no big deal; it certainly would not be a threat to a biblical worldview.

In a fallen world, in which genes are corrupted by random copying mistakes, there may well be adverse effects of such mutated genes on behavior. Pastors know that certain parishioners are more predisposed to a certain class of sin than others. When person ‘X’ falls, it is generally in the same direction—whether that be stealing, pride, gluttony, substance abuse, spousal abuse, infidelity, etc. Person ‘Y’ in the same congregation tends to fall in a consistent direction, too, only it’s not the same direction as for ‘X’. They both have recurring weaknesses, but each is for a different class of sin.

But whatever combination of upbringing, personal habits and/or genetic blueprint may be responsible for a predisposition to a particular sinful behaviour, it’s a moot point because predilection (if it exists) is not predestination. Being predisposed does not mean one is a helpless preprogrammed robot with no moral choice in the matter.

An analogy from medicine might be helpful. A person may be genetically predisposed to type 2 diabetes. But that does not mean that they are helpless victims of their genes either. (They will not usually develop the disease unless they persistently make certain food choices, unfortunately all too common in our age of fast-sugar-release carbohydrates, and not get sufficient exercise, so as to get overweight. Which means that by consistently making the ‘right’ choices, the effects of the inherited programming can be overcome.)

The bottom line is that we are all predisposed to sin in general—that is the basis for the whole message of the gospel—due to our sin nature inherited from the real, literal fall of the first man, Adam (Genesis 3). But because of the sacrificial death of Jesus Christ, the ‘last Adam’ (1 Corinthians 15:45), something truly amazing takes place for those who, by faith, grasp hold of His atoning blood sacrifice for sin, believing that He died and rose again to pay the penalty they deserve.

It happens due to God’s grace, not because of anything they do or have earned in any way. Not only do they receive forgiveness of sin—the slate wiped clean—but they obtain access to ‘power from above’, i.e. the Holy Spirit who indwells all believers (Romans 8:9–11, 1 Corinthians 6:19, Ephesians 1:13, 4:30). They are able to have substantial victory, here and now, over sin in an ongoing fashion.

Does this mean they will never slip and fall? 1 John 1:8–9 says: ‘If we say that we have no sin, we deceive ourselves, and the truth is not in us. [But] if we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.

Regardless of what our predilections or predispositions may be, and regardless whether they are genetic, environmental or a combination of the two, the Bible assures us that ‘Therefore if anyone is in Christ, he is a new creature; the old things passed away; behold, new things have come’ (2 Corinthians 5:17).


  1. The research paper, ‘Genetic Influences on Female Infidelity and Number of Sexual Partners in Humans: A Linkage and Association Study of the Role of the Vasopressin Receptor Gene (AVPR1A)’, will apparently be published in the December edition of Twin Research (Vol. 7, No. 6). A copy of the full research paper is stated to be available from a Matt Akid, at e-mail: matthew.akid@gstt.sthames.nhs.uk. Return to text.
Published: 8 February 2006

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