Avoid Boring People, by James D Watson A Life Decoded, by J Craig Venter

James Watson's demonstration that there certainly is such a thing as bad publicity has left him sadder and us no wiser. First came the quote from the co-discoverer of the structure of DNA: "all our social policies are based on the fact that their [Africans'] intelligence is the same as ours – whereas all the testing says not really." Then came the denial: "there is no scientific basis" for a belief that Africa is "somehow genetically inferior". His UK tour was terminated, as was his chancellorship of Cold Spring Harbor Laboratory. We are left with the book he was trying to promote, and the question: So, what was he thinking?

The question is prompted repeatedly in this latest memoir. Watson reveals himself to be a man of parts, with a rich social hinterland; but he reveals only the sum of the parts. He notes the paintings that his wealth allowed him to collect, but does not reflect upon this aesthetic dimension or any relationship it might have to his scientific thought. Little is done is to offset the sense that he drops the name of Paul Klee in much the same way as that of Sweden's Princess Christina.

Looking back on a career in which he rocketed to the summit of science and jetted through the stratosphere of society, he archly presents a succession of "manners" and "remembered lessons". The latter boil down to the imperative that, when you get to the top, you have to keep climbing. Everything is grist to the mill of status, from a Klee to a TLS subscription, which served to make himself a more interesting guest than someone whose diet was limited to Newsweek.

Unfortunately, he has failed to notice that scientists become boring not when they discourse about science, but when they wallow in academic gossip. His absorption in academic politics also contrasts with the distance he maintains from his own politics. Watson introduces himself as the scion of a staunchly Democratic family and seems to have regularly found himself in leftish company – albeit upper-crust – but is oddly reticent about his own sentiments. It might be fair to say he has been quoted out of context, but that is because he has omitted to provide a context within which he could set his views.

Instead, the reader is left to infer the importance he attaches to the question of race and intelligence from its position as the book's parting thought: "there is no firm reason to anticipate that the intellectual capacities of peoples geographically separated in their evolution should prove to have evolved identically." Having positioned himself so carefully with this studied rhetorical manoeuvre, he then blundered into the sorry mess of contradictions that may prove to be his parting thought as a contributor to public discourse.

By contrast, Craig Venter provides a textbook lesson in how to square genetics and politics. In June 2000 he spoke at the White House event announcing the success of the human genome project. Venter presented his company's work as an exercise designed "to help illustrate that the concept of race has no genetic or scientific basis". He went on to talk about his experience as a medic in Vietnam, where he had seen some men survive devastating injuries while others, apparently less badly wounded, had died after "giving up": "I learned that the human spirit was at least as important as our physiology." This affirmation of the will was as necessary to public support as the denial of race.

Inevitably, other parts of Venter's autobiography throw it into question. The book's unique feature is that it includes information from Venter's own genome, the first individual human genome to be sequenced in full. This is presented in didactic panels, to illustrate some of the findings – sparse, so far – that have been obtained about the association of various genetic sequences with various states of health. One of these mentions a DNA pattern associated with harm avoidance, neuroticism and experimentation with illegal drugs. Where this leaves the distinction between the human spirit and our physiology is not explored.

Where it leaves Venter is also unclear, for the state of genomic knowledge leaves little scope to explore its potential for making autobiography a predictive form. Instead, the book divides broadly into a conventional memoir of a daredevil youth in which his IQ score was a hint of potential rather than a measure of achievement, and a defence of his later career in gene sequencing. Venter has been portrayed by his critics as a rogue researcher bent on making private profits instead of contributing to the public good. He counters that he only took his efforts into the private sector because he was denied public funding, and insists that the pursuit of profit was the means to scientific ends.

Although he accuses his rivals in the public human genome project of many things, he doesn't use their disputes to argue that the private sector is inherently superior to the public. Yet his attention to the details of his salary increases shows that he is not entirely indifferent to money; as does his itemisation of a $30,000 fee incurred when, seeing his stock options lose $300m in value after President Clinton declared that the human genome "belongs to every member of the human race", Venter cancelled the purchase of a $15m schooner.

His adventures under sail form a counterpoint to the extracts from his genome, expressing the elemental side of his drive to "seize life and understand it". In an inspired synthesis of science and sailing, he has combined both parts of his mission statement by launching an expedition to sequence the oceanic genome, crossing the seas and sampling them for genetic sequences, which computers then sort into the genomes of individual organisms. The ultimate goal of Venter's mission, however, is not to seek out new life-forms, but to make them.

He ends his story not with some ominous Watsonian hint about genetic limitations, but with the news that his company is working on genes that could counter climate change by turning microbes into hydrogen fuel cells, and with the vision of "a new phase of human evolution" in which "one DNA-based species can sit down at a computer to design another". His sense of how to connect scientific projects and the public imagination remains as keen as it was on that historic occasion at the White House.

Marek Kohn's 'A Reason for Everything: natural selection and the English imagination' is published by Faber & Faber

Avoid Boring People is published by Oxford £14.99 (347pp) £13.99 (free p&p) from 0870 079 8897

A Life Decoded is published by Allen Lane £25 (390pp) £22.50 (free p&p) from 0870 079 8897

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