Book Review: "Blueprint" by Robert Plomin

This book wasn't on my radar at all and I didn't want to just dive into another science book (you'll see what I'm talking about if you stick around to see what's on in 2026). But it was cheap so here we are. I'm more about reading things that contain ideas I find interesting - which means it is weird that I chose this book because when I was at school, I hated science. I was also really bad at it, I could never understand what was going on but, as I've aged I've developed quite an interest in aspects of it. Learning about us humans is something that I like to read books about (again, stick around for 2026 and you'll see where this is going) and well, Blueprint may have been all about DNA - but I still found it a great read.

Well, as we all know, DNA is a key to shaping who we are and who we become. You might be pleased to hear that and you might not, but there really isn't anything you can do about it. But Plomin builds on this - it isn't just biological. He argues that DNA accounts for roughly 50% of the psychological differences between individuals, from personality traits to cognitive ability. Even our personality becomes part of the DNA analysis stuff we are doing. He states that while the remaining variation comes from the environment, these environmental factors are often random or unsystematic, not stable forces. This was quite enlightening to learn. I often thought that personality and psychology were environmental factors and genetics probably accounted for a very small amount of it. But, as we can see, this is not the case at all. Genetics accounts for a lot of personality traits and probably, some psychological problems.

One of the arguments presented in the book is about polygenic scores. This is how DNA measures predicting traits such as: educational achievement, health conditions, and personality tendencies. Plomin depicts these scores as a kind of “fortune-telling from DNA,” enabling predictions from birth. But on top of this, there is another layer. He actually rejects the environmental theory that states that two children who grew up in the same household will turn out the same psychologically. In twin studies, there has been no correlation found between twin psychology and a shared home space whilst growing up. This is huge for polygenic scores because it solidifies them as the most likely predictor of a child's growth since we cannot rely on the environment as much as we once thought. Polygenic scores can thus predict part of a child’s likelihood of exam success, reading ability, and years of schooling. He shows us therefore, that academic success is largely inherited.

There's something I found quite shocking in this book and I'm going to tell you all about it.There is a controversial argument that parents have far less lasting influence on traits like: intelligence, anxiety, personality, or academic achievement than previously assumed. I would say that there is something to be analysed here. If DNA can predict this stuff, are we actually able to change our futures, or change the futures of those who must grow up with poor academic achievement? There must be something environmental here. I mean, I was quite surprised when I read this. Plomin stresses that differences between siblings arise largely from their different genetic inheritances, not from different parenting styles. Which probably explains why out of the two of us (my brother and I), I'm probably the less intelligent one (nervous laughter ensues across the room). You're allowed to laugh, it's alright - I am well aware.

Plomin goes on though. He explains why intelligence is one of the most heritable psychological traits, and why its heritability increases with age, rising from about 40% in childhood to 60–70% in adulthood. He shows us that intelligence predicts a wide range of real-life outcomes, from physical health to income. I am not going to lie, I would like to think this is a good thing but then again, I cannot help but think that perhaps there is something also environmental here. People who work white collar jobs are more likely to spend more time with their children as more of their time is their own and there is less to worry about. Therefore, passing on this 'intelligence' would be easier than say, a blue-collar worker who would have someone look after the children for many hours of the day since they work longer hours. But, I am still inclined to believe this researcher is telling us exactly what's going on because I mean, I can see myself in the mirror.

I think we all understand that things like: depression, schizophrenia, ADHD, and autism all have substantial heritable pieces. Plomin stresses genetic vulnerability, not genetic destiny which means that they are probabilities, not certainties. We get to look at "pleiotropy" (genes influencing multiple traits), which explains why mental health traits often overlap. I think we tend not to feel like mental health and physical health are two of the same thing but honestly, we need to start thinking that way because mental health problems can destroy your life just as badly and if they have genetic predisposition qualities then we can do more to prevent them. But remember: the government doesn't want you to feel good because if you're sad, you're easier to control and manipulate. That's enough conspiracy stuff from me.

I like the fact he faces some fears head on. He actively confronts ideas such as eugenics and social inequality. He argues that ignoring genetic differences leads to unrealistic expectations in education and social policy. I would say there is an ignorance of structural inequalities but I don't know enough about the subject to base an entire argument on this, so I'll leave it at that. The book is definitely something you should read if you want to blame your ancestors for things they passed on to you - especially if it's stuff like depression, addiction and/or any mental health issues you feel you could do without. But on the whole, I enjoyed this book - it definitely gives me a better appreciation for science.