Lynda I.A. Birke

Progestin-induced changes in play behaviour of the prepubertal rat

The effects of neonatal exposure to medroxyprogesterone acetate on later play behaviour was studied. The experiments reported here indicate that animals of both sexes exposed to the hormone neonatally show lower levels of rough-and-tumble play in the prepubertal period. The effect is primarily one on play initiation: the organisation of play behaviour once initiated is not significantly affected, and the effect on play does not seem to be secondary to effects on some other behaviour. Several hypotheses are considered that might account for these findings.

A sporting chance: The anatomy of destiny?

Abstract We begin this paper by drawing a parallel between womens exclusion from sport and their exclusion from science. Both are stereotypically masculine fields, which women enter only at risk of losing their identity. Moreover, both have justified the exclusion of women by recourse to biological arguments that women are inferior. It is thus not surprising that the combination of these fields in “sports science” adds further justification. We look at some of these biological arguments here, and at how they serve to limit womens participation in sport. Feminists have accepted that biological differences between women and men exist, and have either (i) argued for integration in sports, assuming that the differences are, or will be, unimportant, or (ii) argued for separate spheres, because of existing sex/gender differences. But both of these viewpoints still see our biology as fixed. We argue instead that “biology” can itself be subject to change, and that a truly feminist understanding of women and sport must take the possible transformation of physiology into account.

Beyond nature versus nurture: Process and biology in the development of gender

Abstract The origins of gender, like the origins of human nature, are sometimes said to lie in biological determination, sometimes in social construction. Feminist theory began with criticising biological determinism and its portrayal of women, and inevitably emphasised the social construction of gender. However, seeing gender or human nature as wholly or mainly socially constructed seems to deny the biological processes which comprise our physical experiences of ourselves, and it is this omission which has recently led some writers (both feminist and antifeminist) to lay stress on the significance of biology in human behaviour and its development. These two opposing views of the origin of behaviour are still dominant, despite various attempts to emphasise how biology and social context might interact to produce, say, gender differences: this continued dominance of the nature/nurture duality has considerable political relevance to feminism, and has contributed to the rise of the New Right ideology concerning, for example, the natural role of women and the family. In this paper, we stress the relevance of the nature/nurture duality for this political shift, and attempt to formulate a way out of the impasse. Attempts have sometimes been made to avoid the duality by emphasising the interaction of nature and nurture. However, in most academic writing, the “interaction” proposed fails to avoid the dichotomy completely, and relies on a view of individual development as unfolding towards a goal or plan. The latter is how gender development is typically portrayed, emerging from an unfolding of biological potential (giving rise to “sex” differences), and subsequently from socialisation. It is important for feminism to emphasise the alternative view of biological development, which lays stress on developmental process , of which “biology” is but a part, rather than viewing individuals as maturing or unfolding towards some “goal.” By this change of emphasis, feminist theory may begin to avoid the double pitfall of biological determinism on the one hand; and of constructing “gender” in a world devoid of human bodies, and biological processes, on the other.

Effects of estradiol and progesterone on scent-marking behavior of female rats

The effect of estradiol and progesterone on scent-marking behavior of the female rat is reported. Estradiol followed by progesterone injection to ovariectomised rats results in an increase in marking rates. This suggests an endocrine base to the changes in scent-marking behavior that are known to occur with the rat estrous cycle.

Scent-marking behaviour in response to conspecific odours by the rat, Rattus norvegicus

Abstract The scent-marking behaviour of male and female rats in response to conspecific odours was investigated in two experiments. The results of the first experiment indicated that exposure to conspecific odours generally led to an increase in marking rates. However, no sex differences were found, and large differences in marking responses according to the sex of the odour donor were only found for dioestrous females. These results do not suggest that the primary function of scent-marking in this species is sexual. In the second experiment, odour sources differed not only in the sex of the donor, but also in their relative familiarity to the animal being tested. This experiment showed that males marked more in response to odours from familiar (non-related) females. Females did not differ significantly on measures of marking but did display greater interest in odours from unfamiliar males. The results are discussed in relation to possible functions of marking in this species.

Modification of juvenile play and other social behaviour in the rat by neonatal progestins: Further studies

The effects of altering neonatal levels of progestins on the later development of social play behaviour was studied. Progestin levels were raised in experiment one by administering injections of either progesterone or medroxyprogesterone acetate. This indicated that exposure to either hormone led to reduced levels of social play in juvenile rats of both sexes, confirming earlier reports of lowered levels of play following medroxyprogesterone obtained via maternal milk. In Experiment 2, endogenous progestin levels were lowered by administration of the antiserum to progesterone. The prediction that this should result in raised levels of juvenile play was supported for males, but not for females. Females in Experiment 2 by contrast showed a decrease in play. Possible reasons for this sex difference in response to progesterone antiserum are discussed.

Effects of modulating neonatal progestins and androgens on the development of play and other social behavior in the rat

Rough-and-tumble play is sexually dimorphic in many species of mammals. Effects of androgen exposure on this behavior have been well documented, although the possible role of other hormones is less well known. This paper reports experiments in a series designed to investigate effects of neonatal exposure to progestins on the development of juvenile play behavior in rats. Specifically, the effects of altering levels of progestins and androgens in combination on the subsequent development of play behavior was studied, in order to investigate further the mechanism of progestogenic effects. We have previously [L. I. A. Birke and D. Sadler (1984). Physiol. Behav. 33, 217-219] reported an apparently anomalous effect of lowering endogenous progesterone using the antiserum given postnatally; this was predicted to raise levels of juvenile play. The prediction was, however, supported only for males; treated females showed lower levels of play than controls. The present study was designed to investigate these effects further, and to test hypotheses about the mode of action of neonatal progestins. Using various combinations of neonatal progestins (progesterone or medroxy-progesterone acetate, MPA), and testosterone or the antiserum to testosterone, we analyzed the amounts of play and other social behavior shown by juvenile rats. The data support a hypothesis that the previously reported effects of progestin exposure on play result from weakly androgenic actions of the progestins, which presumably compete with other androgens in males. The cellular mechanisms involved are, however, unknown.

Maternal discrimination and the development of sex differences in exploratory behaviour in infant spiny mice (Acomys cahirinus)

The present paper reports sex differences in exploratory behaviour by infant Spiny Mice, Acomys cahirinus, that may, in part, be related to differences in maternal behaviour towards pups; like some other rodents, mother Acomys differentiate behaviourally between male and female pups. In Experiment 1 infant Acomys were allowed to explore a novel arena. This experiment showed that even by Day 3 (the day of birth=Day 1) female Acomys explored a novel environment more than males; they entered the arena sooner than males and spent more time in contact with a novel object. Experiment 2 showed that infant females were more active than males when observed in the home cage in the presence of their parents and made more approaches to the mother. Mothers, on the other hand, directed more licking behaviour towards males. Experiment 3 focused on the exploratory behaviour of individual pups in the presence of the mother. Given access to a large, complex arena, female pups explored more than males. The results also showed that mothers direct more of their social interactions towards sons than daughters, particularly when pups are about a week old. Some mothers appear to “direct” the movement of their offspring, by blocking their forward movement; this was done more often to male than to female pups. The data suggest that the previously observed changes in exploratory behaviour at this time, and the emergence of sex differences in exploration, may in part depend upon the mothers’ reactions to pups by sex.

Women and microelectronics: The case of word processors

Synopsis The use of microelectronics in production has serious implications for working people, but these implications differ between women and men. We look first at long-wave (Kondratiev) and classical (Marxist) economic theory relate the effects of microelectronics to the economic system. But this tells us nothing about whether the impact of microelectronics differs between the sexes, because the relevant economic categories are sex-blind. The impact on women can only be analysed by introducing the idea of patriarchy. Thus, the interests of capitalists as an oppressor-class and men as an oppressor-sex can be seen as interwoven but not necessarily always coincident. Socialism and feminism oppose different oppressive dynamics, yet a victory for one without a victory for the other would be incomplete. Word processing is an area where socialist and feminist struggles can be joined in a practice which is truly progressive.

Motivation: A New Perspective on Some Old Ideas

An interactive model of motivation is proposed, in which motivational states arise conjointly from internal states (e.g., energy level) and external incentive objects (e.g., an item of food). This model is applied to interpreting experimental evidence on hunger, thirst, sex, temperature control, exploration, aggression, fear, pain, and sleep, It is argued that our understanding of cognitive maps needs to be integrated into our theories of motivation, and a model of Deutsch (1960) is revived in order to serve this end. Foraging is discussed in terms of motivation, cognitive maps, and their interdependence. Decision making is viewed in terms of competition between candidate incentive objects with which the animal may interact rather than competition between motivational states per se.