Firstly the author seems to regard the highly controversial field of so-called evolutionary psychology as being totally reliable. Unfortunately this is not the case, and so we end up with utterly fatuous "explanations" such as this:

Why does the natural waking period for adolescents tend to start and end later in the day?

"Maybe at one point in our history it was important for young people, with good vision and strength, to be more awake and alert later in the day to protect the tribe ... Something is going on that makes adolescents sleep differently than younger kids or older adults"

Despite the fact that this is totally unsupported speculation, albeit by a university-based sleep researcher, it is quoted without the slightest mention that it is reverse logic: Everything is down to evolution, so this MUST have an evolution-based explanation, even if we don't actually have one.

An even more wondrous comment comes from an anthropologist:
"Adolescence is fairly recent ... And it developed because it was a survival mechanism for the species."

Explanation? None.
Supporting evidence? None.

(For a multi-faceted review of Evolutionary Psychology check out "Alas, Poor Darwin", Rose & Rose, eds. ISBN 0-099-28319-0.)

The second bias follows directly on from the first, namely that the book heavily favours evidence that supports a genetic cause for just about everything. Even when nurture is allowed in we seem to end up with the argument that environmental influences simply trigger genetic propensities.

And what about this piece of self-contradiction within a single paragraph:

"Generally we follow a twenty-four-hour cycle, a time frame probably set when amoebas reacted to the turn of the earth on its axis. Studies of those who've volunteered to live in caves or dark labs, though, find that most will push the cycle a bit out of sync, to about 25 hours..."

Sorry? We've inherited a twenty-FOUR hour cycle from our distant ancestors, YET when left without external controlling influences we revert to a twenty-FIVE hour clock? Where did we get THAT from?

As usual there is no discussion of the evolutionist "explanation".

This second bias appears to be due, in part, to the author's unquestioning acceptance of studies of identical twins. Which is unfortunate, to say the least, given the questionability of such studies as outlined in "They ...You Up" (asterisks as in the original) a new book by child psychologist Oliver James which tackles many of the same topics.

The third bias follows from the first two - adolescence is discussed in almost total isolation. This is hardly surprising, of course, since the notion that adolescent changes are almost entirely genetically based means that the pre-teenage years become irrelevant. To judge from this book the first decade of human life is of little or no account, and the biological and neurological changes which mark the onset of adolescence must somehow "wipe the board clean" so that we effectively start as brand new people at around age 10-12.

Not only is this psychological nonsense, but some of the thinking that arises from such ideas is potentially extremely damaging. One researcher, described as a "behavior professor", is cited (but not directly quoted) as saying that once young people have the functioning parts there is little reason for teenagers to refrain from having sex. Indeed, we are told that the professor "concluded that [the] reticence [of teenagers who don't opt to have sex as soon as they have the 'functioning parts'] must have been due to an immature brain." (pages 158-9).

Apparently for some the fact that we have far more complex and sophisticated brains than we could possibly need for mere survival - and are NOT utterly dominated by our instincts - is a mere bagatelle. Coming from a country that is already amongst the world leaders for unwanted teenage pregnancies and the incidence of sexually transmitted diseases, that might warrant the raising of an eyebrow or two.

Well-written, interesting, but ultimately very deeply flawed.
Best consumed with a king-sized helping of healthy scepticism.