In both sexual and non-sexual intimate relationships, the boundaries protecting the inner self are relaxed, so that our respective inner selves become shared territory to the extent that our thinking and emotions are shaped by each other’s presence.41 With interpersonal attraction (as against sexual attraction), there is a desire to encounter the inner self of the other person so that our inner selves might become ‘shared territory’, as well as enjoying the more ‘superficial’ qualities of the person. In these circumstances there is no sharing of our respective bodies. But in a functional sexual relationship, there is a desire to encounter both the inner self and the body of the other person: the sharing of interpersonal territory occurs at both physical and relational levels.42 And probably the most profound and enduring extension and expression of this ‘shared investment’ or ‘mutual belonging’ is in the birth of a child into the relationship — the child belongs to both parties and both parties belong to the child. Belonging forms a primary function in a sexual relationship, and the drive to belong quite appropriately finds expression in sexual behaviour.
Karl’s reaction after his visit to the prostitute revealed that drives were present of which he was not aware — his visit had satisfied some drives, but not others. What was the nature of his various drives? What made him visit the prostitute, a visit that left him vaguely unhappy? What makes him do anything? This is another way of asking: what are the underlying forces or motives that energise and direct Karl’s behaviour? What was he wishing to achieve in his visit to the prostitute — what was his conscious or unconscious goal? Is there such a thing as a biological ‘sex drive’ that ‘caused’ him to desire and engage in sexual behaviour with the prostitute? But how might such a drive discriminate with whom and under what circumstances he should have a sexual encounter? Karl’s experience suggests that it was not a single drive, biological or otherwise, conscious or otherwise, that energised his actions: several drives appeared to be operating simultaneously, and not all those drives were fulfilled in his case. Moreover, in this mix of drives, some serve to make him want something, others to actively avoid something. But what were these drives?
The idea that a mix of drives prompted Karl to do what he did can also be used to explain why others enter into sexual encounters and relationships of one sort or another. Moreover, to explain the many ways in which sexual behaviour is expressed, I propose that the composition of drives varies between people, and over time in any one person. Theoretically, identifying different drive combinations might help us predict with whom and under what circumstances a person has a sexual encounter or relationship. Fleeting sexual encounters will generally involve different drive combinations than long-term sexual relationships, while relationships of convenience will generally involve different drive combinations than romantic ones. In like manner, sexual variation emerges from variation in drive combinations. But what drives comprise these drive combinations? How can such drives be identified and measured, and how might different drive combinations form? I will argue that there are both biological and subjective aspects to these drives, forcing us into a dualism of some kind. I will argue for an interactive dualism, rather than for parallel and independent processes in the biological and subjective spheres.
Drive theory: What prompts me to do something?
A drive is a subjective motivating urge that stimulates behaviour. It is a force that energises and directs an action or activity. It reflects an incentive towards a particular goal and is the basis upon which we might say ‘the reason or purpose for doing something is such and such.’ However, the term ‘drive’ has had particular meanings in the history of psychology. Early drive theorists conceptualised drives (or ‘instincts’) as essentially mechanical and deterministic in nature, where an irresistible physiological need aroused and energised a person to activity, reducing discomfort or maximising pleasure in relation to the physiological need.43 While avoiding notions of goal or purpose in describing behaviour, behaviour theorists argued that the behaviours such drives energised were shaped by a person’s learning history, whereby the learned habit patterns determined how a person might satisfy relevant physiological needs.44 Reinforcement schedules and conditioning theories explained the links between drives and observed behaviours. The satisfying of the physiological drive established the reinforcement value of the relevant behaviours, thus forming the basis of the habit pattern. This conditioning theory underpinned psychological interventions of the 1960s and 1970s, including interventions relating to sexual behaviour and orientation, with varying success.45
However, the idea of a drive as simply a physiological energy system directing behaviour failed to explain many behaviours. There needed to be a subjective dimension to drives — a dimension involving a person’s perceived needs and desires. Indeed, we know that subjective perceptions and their associated desires can overpower physiological needs. And so some earlier theorists cast a wider net to the question of what motivates us to do things, such as Murray in his ‘universal needs’, Miller in his ‘conditioned motives’; and others who proposed various ‘mini-theories’ of motivation.46 Each of these contributions offered particular insights into the complex interaction of drives that energise behaviour.
Nevertheless, because of the problems inherent in measuring and predicting drives, motives, incentives and intentions, and because of the complexities such notions added to experimental design, they lost their appeal as explanatory mechanisms in evidence-based psychological theory and research in subsequent decades. But this did not mean the notions themselves were invalid or outdated; from a clinical perspective, they remained central constructs.47 We return to these ideas, but make distinction between our use of the term ‘drive’ and that used in traditional drive theory. Our focus is on the subjective aspect of drives — whether the drive source be subjective or physiological. To gain insight into the interplay of the subjective and physiological components of prevailing drives, let us leave the subject of sex for a moment and consider an equally fundamental activity: eating.
We all understand the need to eat. This need has an obvious primary physiological function: that is, to provide nutrition for the body. Normally, when the physiological need arises, the body generates hormones creating a desire to ingest food — that is, it creates hunger signals.48 While the source of these signals may be biological, they are apprehended by the subjective self, creating a felt urge — a ‘drive’ to eat. Yet the need to eat does not discriminate what food is good for the health of the body, even though a primary function is to keep it healthy. Furthermore, competing motives affecting eating behaviour may have little to do with this physiological need and primary function. Take, for example, the person suffering an eating disorder,49 or choosing to fast until they get political demands met: here the physiological ‘need to eat’ is suppressed. If we were to define a drive by its goal, we would find many different goals for eating (or not eating): I might eat because it is dinnertime, because I am bored, because I feel sad, because the food looks/smells good (for pleasure), to celebrate, to be nurtured emotionally, to be social, to make a political statement and so on. The goal becomes the defining element of the subjective drive, a drive that can have more to do with the state of the inner self or with social demands than with bodily needs.
And so we see that different subjective drives can relate to the same behaviour: in this case, whether or not to eat. A drive can be linked to a physiological need (eating to satisfy felt hunger that signals physical needs), or to other