Target tissue sensitivity, testosterone and social environment
interactions, and lattice hierarchies
Kathleen C. Chambers
One must consider not only the levels of circulating hormone but the
target tissue upon which the hormone acts.
Increased testosterone levels alone do not account for differences in
displayed intermale aggression because testosterone and social
environment interact in complex ways to influence behavior.
This commentary is written from the vantage point of a researcher who
up until recently has used animal models exclusively to study
interactions between gonadal hormones and behavior. There are many
subtle and not so subtle differences in the nature of these
interactions among various species as well as among various strains of
a given species. Thus one would not expect that one animal model could
serve as a perfect model for the nature of the interactions in humans.
Chambers acknowledges that animal studies that she has conducted
often result in differing findings, this demonstrates that different
species react differently to hormones. Chambers then goes on to use
these studies to make inferences about the human species. Surely if
there are differences between animal species in their reaction to
hormones, it is highly likely thet human behaviour will also differ
considerably. Perhaps Chambers should not make inferences about
human behaviour based on findings from amimal studies.
The concept of 'tissue sensitivity' has been used to account for
individual, sex, and strain differences and for age-related changes in
the threshold amount of hormone needed to activate various behaviors
influenced by gonadal hormones
I presume that this is refering to the amount of testosterone that
is active in a persons body.
The specific mechanisms that determine tissue sensitivity remain
unknown but several possibilities have been suggested: decreases in
the availability of testosterone or the active metabolites of
testosterone at the receptor sites in the target tissues, decreases
in the total available cellular receptors, qualitative changes in the
properties of the receptor, such as a decrease in affinity of
receptor for the hormone or a change in hormone specificity, and
changes in the hormone-receptor-nuclear chromatin interaction.
There appears to be no specific definition or measure of 'tissue
sensitivity', several possible examples are given but there is no
evidence which is given to back up any of the possibilities.
In those behaviors studied, differences in tissue sensitivity are
due to differences in the availability of testosterone during the
prenatal-early postnatal developmental period.
How can this be claimed if the mechanism that determines tissue
sensitivity is unknown? No explanation was given as to how the
tissue sensitivity was measured?
Thus in human males, differences in aggression may be associated with
differences in testosterone availability during this developmental
period which then leads to differences in tissue sensitivity to
circulating testosterone in adulthood.
The first problem with this statement is that it is based on animal
studies and has been generalised to human males. Secondly, Chambers
has found an association between aggression and high levels of
testosterone which shouldn't occur, as many males with high
testosterone are not aggressive (Chambers, herself has admitted that
not all high testosterone males are aggressive).
This association may have been found as a
result of studying animals and not humans. This highlights the
problem of generalising animal study results to humans. The third
problem is that an explanation of the measure by which tissue
sensitivity is determined, is not given.
There is evidence in other social animals that hormones and social
environment interact in complex ways to influence behavior. The
authors acknowledge this interaction when they discuss the reciprocal
linkage between hormones and behavior (Honor Subcultures, paragraph
Chambers seems to be agreeing that the histories and experiences of
humans do influence their behaviour in the presence of
testosterone. So, from initially saying that aggression and
behaviour can be predicted from tissue sensitivity and testosterone
levels, she is now suggesting that actually behaviour is also
determined by past experiences. This in fact leaves no room for
prediction whatsoever, as you will never know all of a persons
However, in animals, increased systemic testosterone levels alone do
not account for differences in displayed intermale aggression but the
combined interaction of sufficient testosterone, previous social
experience, and present social status do. For example, even though
two males may have high testosterone levels in the same situation,
whether they will display aggression is dependent on their prior
This distinction, can be made between animals because they can be
observed and controlled throughout their lives, however this is not
the case in humans, as it is not ethical and so testing such a
theory is probably impossible.
If, as the authors suggest, testosterone is associated
with dominance behaviors in prosocial as well as antisocial men, then
one must still account for why, in the presence of sufficient
testosterone, some men direct their dominance in an antisocial
direction whereas others do so in a prosocial direction (Summary and
As always the answer could be that the behavioural reaction to
testosterone is genetic or socially learned throughout life.
Both of these explainations could be argued. The 'Honour Culture'
could be taken as evidence that aggression in the presence of
testosterone is a learnt association, brought about by the need to
fight to protect yourself. However, it could also be suggested that
it is genetically passed on through generations of the honour
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