Metabolic systems are complicated and contain very large numbers of interacting reactions and many internal regulatory mechanisms. This does not prevent the genetic composition of an organism from influencing its behavior, however, nor does it preclude the possibility that some aspects of its behavior may be amenable to simple explanations.

Rose's Lifelines justifiably attacks the rigid genetic determinism that pervades the popular press and even some scientific writing. Genes do not equate with destiny. However, Rose's argument should not be taken too far: genes do influence behavior, in animals as well as in man.

Lifelines supports the theme that behavioral development is a fluid, life-long phenomenon. In contrast, many emotional and cognitive traits are subject to strong genetic influence, and are highly stable over many years. The manner in which neuroplasticity and trait stability cooccur needs to be modeled. An outline of such a model is provided to promote discussion of this complex issue.

Professor Rose is inflamed against the views of Richard Dawkins concerning genetic determinism. He has constructed an image of a much stupider and eviller Dawkins view than is likely to be true and argues against it. This is unrewarding, but otherwise his discussion of biology is very interesting.

In “Lifelines” Steven Rose constructs a case against neurogenetic determinism based on experimental data from biology and in favor of a significant degree of self determination. Two philosophical errors in the case favoring neurogenetic determinism are illustrated by Rose: category mistakes and an excessively narrow view of causality restricted to the linear form.

Although Rose claims to rely on Marx's paradoxical view of history to explain the freedom enjoyed by what he calls “lifelines,” he blurs what one might call the “objective” and “subjective” senses of freedom. This, in turn, reflects his overreaction to biological reductionism. Consequently, in discussing biology-related policy issues, Rose fails to distinguish genuinely efficacious interventions and merely convenient ones.

Rose's accomplishment in combining ontological unity with epistemological diversity contrasts it with Wilson's failure in overemphasizing the former and not appreciating the latter. This commentary cites the two most authoritative discussions of the inapplicability of heritability to human data, corrects several historical errors or inaccuracies in genetics, and criticizes the characterizations of Jacques Loeb and Robert Plomin.

Stephen Rose's formulation of evolutionary theory is too scattered and impressionistic to serve as a genuine alternative to ultra- Darwinism. In addition, he has muddied a distinction that is crucial to our understanding of evolutionary phenomenona – the distinction between homologies and homoplasies.

Rose provides a coherent account of how a number of simplifying assumptions apparently come together to support neurogenetic determinism, or “ultra-Darwinism.” This view, he demonstrates, is deeply flawed. He proposes instead that we must take account of the interaction of processes that determine our developmental trajectory at every stage. Unfortunately, he associates this defensible position with the claim that this gives freedom of action to humans. The implications of this for the interpretation of his general thesis are discussed.

Rose seems to be arguing against an extreme ultra-Darwinism that probably has no adherents. He incorrectly argues that a number of psychological traits are very difficult to measure. This is not the case. Rose argues that intelligence has no biological correlates. In fact, it is correlated with brain size, EEG evoked potentials, and cerebral glucose uptake during problem solving. Data that Rose should be aware of are omitted when they do not fit the case he is trying to make.

Lifelines by Steven Rose is supposed to present a new perspective on biology replacing an emphasis on genes with one on organisms. However, much of the book is a highly biased critique of sociobiology and behavior genetics. Some of the flaws in Rose's description and depiction of these fields are presented and refuted. Also, it would appear that these aspects of the book and many others are, in fact, related more to Rose's perennial concern for the ideology, social origins or social consequences of behavioral biology. These concerns are, I believe based, in part, upon Rose's misunderstandings and misinterpretations of genetics, behavior genetics, and sociobiology.

Research pragmatics, not a defective conceptual framework, supports modern biological reductionism. Conducting research to reveal the casual web underlying the multiple developmental pathways leading to any species-specific characteristic requires better research techniques than those commonly used. It takes much patience, time, and effort to gain even small glimpses of an answer to any developmental question.

Complete determinism is, as Karl Popper said, “a daydream of omniscience.” Determinism is usually conceived as linked with a particular science whose explanations are deemed fundamental. As Rose rightly points out, biological enquiry includes many different kinds of question. Genetic determinism, making genes central to biology, is therefore biased and misguided. The crucial unit must be the whole organism.

Rose presents an important critique of the determinism and reductionism of modern biology. However, such trends are probably temporary aberrations in the development of science. Another form of determinism which has deeper roots is emerging from modern studies of brain dynamics. To reconcile this evidence with the concept of a “person” will require more radical rethinking of our received notion of natural law.

Steven Rose's book is essentially a plea for considering the variety and complexity of life and against simplistic reductions of human and animal behavioral phenomena to single genetic causes.

Extending lifelines still further, beyond determinism leads to doubt about females' ability to select mates with “good genes,” and to a scenario for troop selection and to a link with questions of scale in ecology.

While agreeing with Rose's reasoning about why the causes of organisms' behaviors cannot be reduced to the solely biological and molecular, this review questions Rose's uses of the terms “determinism” and “contingency”; his occasional seemingly cavalier acceptance as fact of unproven hypotheses about social and psychological phenomena; and his general disdain for the psychometric tradition and its causal modeling extensions.

The derivation of heritability from human twin studies involves serious methodological flaws. Heritability is consistently overestimated because of biological confounds of twinning, consistent and often gross underestimation of the environmental variance, and nonadditive genetic influences that can hugely exaggerate heritability values. Despite this bad research design, behaviour geneticists continue to publish results implying that their heritability results are valid.

The major merit of Rose's book is the elaboration of the idea of multilevel causation in different explanatory languages. Yet Rose's critique of “ultra-Darwinism” is not convincing. Rose argues that activity and self-replication are properties of organisms rather than genes, which contradicts his idea of multilevel causation. Also, Rose fails to develop the concept of multilevel selection.

Many of Rose's criticisms of determinism in biology have clear relevance to modern cognitive and psychiatric science; too narrow a focus on the brain as an information processing machine runs the risk of neglecting the context in which information processing takes place, and too narrow a focus on the neuroscience of psychopathology runs the risk of neglecting other levels of explanation for these phenomena. It should be emphasized, however, that animal and genetic studies of phenomena of interest to cognitive and psychiatric science (e.g., Alzheimer's disorder, schizophrenia, attention deficit/hyperactivity disorder, and violence), while perhaps only providing a partial perspective, may be useful in understanding these phenomena and in leading to appropriate psychiatric interventions.