Publicado originalmente en FaceBook, 2009.

Llevo varios años leyendo artículos acerca de los cerebros masculinos y femeninos. Acabo de conseguir un libro que es realmente sobresaliente como referencia del tema (Hines 2004). Esta es la conclusión (no puedo traducirla, es muy larga).

Understanding the range of factors that influence behaviors, includ-
ing, but not limited to, hormones, can permit the choice of levels at
which to intervene, should intervention seem desirable. Thus, even
though a psychological characteristic may be found to involve innate
predispositions, either genetic or hormonal, it might be preferable
to change it through other mechanisms. The treatment of individu-
als suffering from psychological depression provides an example of
this approach. Although depression has been found to have a strong
genetic component, it can be treated effectively with talking thera-
pies, particularly cognitive-behavioral therapy.

One unfortunate consequence of individual scientists viewing
psychological characteristics, such as occupational possibilities, ag-
gression, or child-care abilities, through the lens of a single research
perspective has been a tendency to see individual human potential as
more limited than it, in fact, is. Because those exploring hormonal
explanations have been relatively unaware of social influences, for in-
stance, they tend to see limitation, such as sex segregation in occupa-
tions, unavoidable aggression, or limitation on abilities to nurture. A
broader perspective leads to the conclusion that even if hormones
contribute to a behavior, it is still possible to influence it by other

Expectations and beliefs, as well as hormones, can engender the
brain. One of the fundamental contributions of psychology as a field
has been to document empirically that expectations can cause dra-
matic behavioral changes. Placebo effects are one example. People
led to believe that they are being given a treatment (e.g., a pill) that
will cause certain effects will often show those effects, even though
the pill contains only an inert substance. This explains the efficacy of
sugar pills in treating a variety of ailments, and, as pointed out in
Chapter 7, may be part of the explanation for the belief that taking
androgen makes men aggressive. Within the academic setting,
Rosenthal and Jacobson (1968) demonstrated similar effects in stud-
ies where teachers were told that certain students would show im-
proved academic performance. Although the students had been ran-
domly selected to be labelled as about to improve, the belief of the
teachers in their potential led them to perform better than other

More specifically relevant to the research summarized in this
volume, press reports of female disadvantages at mathematics have
been found to lead to reduced expectations of good mathematics
performance by parents of girls (Jacobs and Eccles, 1985). Parental
expectations could affect performance directly, as did teachers’ ex-
pectations in Rosenthal’s studies. In addition, parental expectations
influence the expectations of their children (Tiedemann, 2000), and
individual expectations or apprehensions have been linked to math-
ematics performance (Frome and Eccles, 1998; Spencer et al., 1999).
Similar links between beliefs about women’s poor performance have
been linked to a reduced interest among women in math, engineer-
ing, and science (Correll, 2001). Thus, reports that hormones cause
girls or boys to perform more poorly in certain areas or limit their
occupational prospects, even when erroneous, are not benign.

The observation that some sex differences in human behavior
relate to sex hormones has led some to conclude that all sex differ-
ences in behavior, social roles, and occupational status are based on
innate factors. This has resulted, for instance, in suggestions that the
abilities of males to care for children are limited or that men and
women will never be equally distributed in certain professions. The
empirical data on hormonal influences on the brain and behavior
suggest flexibility and variability in outcomes that argue against these
conclusions. The generalization of conclusions from one specific
finding to a more global explanation may relate to gender schemas.
As noted in Chapter 7, these schemas can lead to overgeneralization
from one piece of evidence supporting a stereotype to the conclu-
sion that all facets of the stereotype are accurate.

The history of basic research on hormonal control of sexual dif-
ferentiation has led to many surprising conclusions: that hormones
can override information from the sex chromosomes in determining
sex-related characteristics; that androgen is converted to estrogen
within the brain before exerting some of its influences; and that the
ovaries are not needed for most aspects of female-typical develop-
ment. Our gender schemas, or stereotypes about sex differences and
their causes, have sometimes led us to believe that hormones have
behavioral influences where none exist, or, that where they do exist,
they are more immutable or limiting than is the case. Empirical re-
search on hormones and aggression and cognitive function in hu-
mans has produced some results that challenge widely held stereo-
types about sex differences. Similarly, human gender identity has
proven to be surprisingly flexible. In addition, recent research sug-
gests that the adult brain is remarkably responsive, even in terms of
its structure, to experience, as well as to hormones. If we can treat
sex more like other areas of inquiry, trying to put gender schemas
aside, or at least be aware of them, I suspect that there will be more
surprises in store.

HINES, M. (2004) Brain gender. Oxford: OUP. 226-228.