Max Carter ... in control of his mum's pleasure centre.

Max Carter ... in control of his mum's pleasure centre.

I hated being pregnant – nausea, back pain, severe exhaustion … and I looked like a hippo.

The labour and birth were even worse.

People often talk figuratively about how "rewarding” children can be. But are children also rewarding in a literal sense? 

These days I’m woken throughout the night by a screaming baby and coughing toddler. I carry a constant smell of baby vomit and in the last week have needed treatment for my bad back and shoulder. Of course, we can’t forget the stinky nappies and endless loads of washing.

So, given this picture of hell, how can it be that having children is the best thing that’s ever happened to me? I love it. I obviously love my kids, but what I find most remarkable is how much I am enjoying this period of life.

As a scientist, I’m pathologically rational. So I have been trying to understand how an overwhelming positive could result from the combination of so many negatives. But as I look at my little baby Max, I think I have the answer: I am addicted.

People often talk figuratively about how "rewarding” children can be. But are children also rewarding in a literal sense? (Certainly not in a financial sense!) What if you go past money and material possessions and look deep into the middle of the brain – where the purest feelings of emotional positivity are generated?

After the chaos of breakfast has past and I finally get some one-on-one time with little Max, I find I just can't help myself.

"Daa boodle doodle kikik … Daa boodle doodle kikik … Ahh boo … Ahh boo!"

Max rolls his huge eyes over to me and starts to chuckle. Ahh, jackpot!

It’s funny to think a few years ago I was working 70 hours a week as a research and teaching fellow at Harvard University, and now all my physical and mental energies are consumed by trying to make a three-month-old baby smile.

So could it be that my baby is tapping directly into my brain’s reward center? I figured somebody must have studied this. Sure enough, an apply titled study – What’s in a smile? Maternal brain responses to infant facial cues – recently found that baby smiles do indeed activate exactly the same brain networks as those affected by drugs such as cocaine or a jackpot at the pokies.

I guess if you think about it, the sole evolutionary purpose of the brain’s reward network is to promote behaviour that increased the chances of passing on one's genes by producing fit and healthy offspring (the system can then be hijacked by addictive drugs and other harmful addictions).

So essentially, every smile from Max is sending a little message to my brain saying: “That was good, Mum – do it again!”

This article first appeared on The Conversation.