Evolutionary psychology is a field of science that looks at human behaviour in terms of evolution. Some of our habitual or instinctive behaviours have developed that way and are encoded in our brains because these behaviours lead to the survival of the species.

These types of behaviours include attraction to the opposite sex  (for reproduction) protection of offspring, seeking food or shelter (nesting) and general response-to-threat behaviours.

I remember a particularly interesting trip with my 3 children to the “Crocodile Farm” in Cairns. On arrival I became nervy and irritable, I wanted to make our trip as short as possible and I got very prepared to fight irrationally and seriously with my husband when he tried to take the children somewhere. Basically I was quite prepared to do whatever it took to remove the threat. But it took a while for me to realise that what i was actually afraid of was the Crocodiles! Because a lot of the time, evolutionary behaviours occur on an unconscious level – they are instant reactions that occur in the “anxiety centre” or brainstem, and bypass the logical thought centres (cortex) of the brain.

So in mental health anxiety is often seen as an evolutionary behaviour. Our nervous systems have evolved a “fight or flight” response to any kind of perceived threat. This involves certain body sensations (increased heart rate, muscle tension etc) which prepare us to literally fight or run – and other responses here might include a “freeze” response which happens in some kinds of anxiety.

Looking at mothers with new babies, all our evolutionary responses are maxed out because we are programmed to protect this new little life. This leads to the “mother bear” syndrome when some of us will go for anyone’s jugular if they seem to be threatening our baby. This includes fathers, when they seem to be putting the baby in danger.

So how does this work for postnatal disorders. We all know about postnatal depression and how common it is. Anxiety symptoms are very common and is intimately connected to depression, so much that some even say they are the same thing.

We have all seen worrying mothers and anxious mothers and fiercely protective mothers. When does this cross the line and become a disorder? Maybe some of our behaviours and body responses were adaptive when we used to live in the savannah surrounded by possible predators. We had to find shelter and food, avoid threats and stay with the group to survive. These responses can work against us in the society in which we now live.

Some common anxiety disorders are:

– panic disorder and agoraphobia (fear of open spaces) people become anxious when out in the open – a primal fear of exposure to predators, and this is associated with panic attacks.

– social anxiety – people are afraid when around their friends or community and fear rejection by the group, sometimes worrying about their own appearance – this dates back to a time when rejection by the group could mean death, and perhaps those who looked different were rejected because it might mean disability and threaten the survival of the group. But the result of this kind of anxiety can be that people actually avoid the group and inadvertently create what they fear – isolation.

– obsessive-compulsive disorder – a classic feature is fear of germs and compulsive hand washing – related to fears of disease and death. Again this becomes worse with a small baby as a protective mechanism gone wrong and can sometimes cause harm to the baby through excessive cleaning or lack of affection. I have met women who fought bitterly with their husbands about hygiene, not realising they were literally fighting for their lives.

So that’s how anxiety disorders in pregnancy and postnatally are related to evolution. It kind of makes sense when viewed in the context.

The solution is to encourage people to see their thoughts more rationally and logically, and evaluate the reality of the situation. Is there any threat and what is the outcome of their conditioned behaviour. Is the anxiety harming or helping, and how to come up with more logical thinking or helpful behaviour. We need to activate our higher thought centres (cortex) and integrate it with the anxiety centre (brainstem) to calm it down. The good news is those pathways do exist and can be developed, as neuroscience research shows.