Matt Ridley

Le premier marqueur génétique de Plomin, le IGF2R sur le bras long du chromosome 6, n'est pas exactement, à première vue, un bon candidat au titre de « gène de l'intelligence ». Sa première prétention à la célébrité, avant que Plomin ne l'ait corrélé à l'intelligence, était d'être associé au cancer du foie.

Pour le philosophe Tony Ingram, le libre arbitre, c'est ce que nous prêtons aux autres – il semble que nous ayons un préjugé intérieur nous faisant attribuer un libre arbitre à tout le monde et tout ce qui nous touche de près, depuis le moteur de hors-bord récalcitrant jusqu'aux têtes à claques qui ont hérité de nos gènes.

The effect is named after the famous story of President Calvin Coolidge and his wife being shown around a farm. Learning that a cockerel could have sex dozens of times a day, Mrs Coolidge said: "Please tell that to the president." On being told, Mr Coolidge asked, "Same hen every time?" "Oh no, Mr President, a different one each time." The president continued: "Tell that to Mrs Coolidge." (cit. p. 290)

6. « Our minds have been built by selfish genes, but they have been built to be social, trustworthy and cooperative. That is the paradox this book has tried to explain. Human beings have social instincts. They come into the world equipped with predispositions to learn how to cooperate, to discriminate the trustworthy from the treacherous, to commit themselves to be trustworthy, to earn good reputations, to exchange goods and information, and to divide labour. In this we are on our own. No other species has been so far down this evolutionary path before us, for no species has built a truly integrated society except among the inbred relatives of a large family such as an ant colony. We owe our success as a species to our social instincts ; they have enabled us to reap undreamt benefits from the division of labour for our masters – the genes. They are responsible for the rapid expansion of our brains in the past two million years and thence for our inventiveness. Our societies and our minds evolved together, each reinforcing trends in the other. » (p. 249)

Steven Pinker [...], tout en adhérant à la théorie du gène égoïste, a choisi de ne pas avoir d'enfants, et ne s'est donc pas fait faute de dire à ses propres gènes égoïstes d' « aller se faire voir ».

Les 7 morales du ch. X : « Morale n° 1 : Don't be frightened of genes. They are not gods, they are cods. - Ne craignez pas les gènes : ce ne sont pas des dieux mais des rouages. 
Morale n° 2 – Les parents : Being a good parent still matters. - Être un bon parent, ça a encore son importance.
Morale n° 3 – Les pairs : Individuality is the product of aptitude reinforced by appetite – L'individualité est le produit des dispositions renforcées par les désirs.
Morale n° 4 – La méritocratie : Egalitarians should emphasise nature, snobs should emphasise nurture – Les égalitaristes devraient mettre en exergue la nature, les snobs les acquis.
Morale n° 5 – La race : The more we understand both our genes and our instincts, the less inevitable they seem. - Mieux l'on comprend à la fois nos gènes et nos instincts, moins ils ne nous semblent incontournables.
Morale n° 6 – L'individualité : Social policy must adapt to a world in which everybody is different. - Les politiques sociales doivent s'adapter à un monde où chacun est différent.
Morale n° 7 – Le libre arbitre : Free will is entirely compatible with a brain exquisitely prespecified by, and run by, genes. - Le libre arbitre est entièrement compatible avec un cerveau prédisposé et opéré par les gènes dans les moindres détails. » (pp. 250-275)

« A mouse shares much of its genetic code with a human being. Oxytocin ans vasopressin are identical in the two species and are produced in the equivalent parts of the brain. Sex causes them to be produced in the brain in both human beings and rodents. Receptors for the two hormones are virtually identical and are expressed in equivalent parts of the brain. Like those of the prairie vole, the human receptor genes (on chromosome 3) have a – smaller – insertion in their promoter regions. Like the prairie voles of Indiana, the lenghts of those promoter insertions vary from individual to individual : in the first 150 people examined, Insel found 17 different promoter lenghts. And when a person who says she (or he) is in love contemplates a picture of her loved one while sitting in a brain scanner, certain parts of her brain light up that do not light up when she looks at a picture of a mere acquaintance. Those brain parts overlap with the ones stimulated by cocaine. All this could be a complete coincidence, and human love may be entirely different from rodent pair-bonding [… !] » (pp. 46-47)

« Nurture is reversible ; nature is not. That is the reason responsible intellectuals have spent a century preferring the cheerful meliorism of environment to the bleak Calvinism of genes. But what if there were a planet where it was the other way round ? Suppose some scientists discovered a world in which lived intelligent creatures whose nurture was something they could do nothing about, whereas their genes were exquisitely sensitive to the world in which they lived.
Suppose no more. In this chapter I aim to start convincing you that you live on precisely such an invented planet. To the extent that people are products of nurture, in the narrowly parental sense of the word, they are largely the products of early and irreversible events. To the extent that they are the product of genes, they are expressing new effects right into adulthood, and often those effects are at the mercy of the way they live their lives. » (p. 151)

"[...] evolution is more about reproduction of the fittest than survival of the fittest; every creature on earth is the product of a series of historical battles between parasites and hosts, between genes and other genes, between members of the same species, between members of one gender in competition for members of the other gender. Those battles include psychological ones, to manipulate and exploit other members of the species; they are never won, for success in one generation only ensures that the foes of the next generation are fitter and fight harder. Life is a Sisyphean race, run ever faster towards a finishing line that is merely the start of the next race." (p. 168)

"If I am to sustain my argument that genes are the root of nurture as well as nature, then I must somehow explain how genes made culture possible. Once again, I intend to do so, not by proposing 'genes for' cultural practice, but by proposing the existence of genes that respond to the environment, of genes as mechanisms, not causes. [...]
I believe that the human capacity for culture comes not from some genes that co-evolved with human culture, but from a fortuitous set of preadaptations that suddenly endowed the human mind with an almost limitless capacity to accumulate and transmit ideas. Those preadaptations are underpinned by genes." (p. 208)