identify the strength of all relevant factors, we can accurately calculate the outcome. These factors are irresistible and inevitable, they can be measured and their action predicted: they just are. These cause-and-effect relationships remain true and unchanged, across time and across people. It is a closed and deterministic system. Scientific explanation is an explanation that describes events in terms of these cause-and-effect laws.
Psychological science, however, needs to deal with another dimension that interacts with natural laws and their inherent predictability: the dimension of the subjective self. This is the dimension of ideas, meanings, and reasoning, of decision-making and independent initiative. The laws it obeys are not the same as those of natural laws. It is no longer a closed and deterministic system. Rather than cause-and-effect, it is about subjective perceptions that form the basis for reasoning and action. It is about the purpose and function of behaviour — the intent and motives. The rules that govern these are not irresistible or inevitable as natural laws are, and they are not easily measured or accurately predicted. They have the capacity to change across time and across people. Nevertheless, they are not random or without reason. But the reason for such behaviour relates to subjective perceptions, prevailing emotions, and personal goals — behaviour is not just the inevitable outcome of prevailing forces; it can be said to have a purpose.
We might say there are natural laws and supernatural laws, in the sense that the latter deal with laws that may be superimposed upon the former natural laws. The natural laws are never suspended, but may be interfered with by ‘supernatural’ laws that govern the actions of the subjective self. And so the study of natural laws remains relevant in psychology. As human beings, we simultaneously inhabit bodies subject to natural cause-and-effect laws, and have minds that can make subjective decisions that ‘interfere’ with these natural laws, bringing about different outcomes. These, then, are reflected in the two drive sources, one obeying natural laws; the other obeying ‘supernatural’ laws. It is the ‘supernatural’ laws of the subjective self that submit to legal and moral considerations in a way that natural laws never could.57
In the present conceptualisation of a dual-drive model, the first drive source is neurobiological and governed by natural laws. That is, the drives involve the neuroendocrine system with its associated hormones, peptides, and neurotransmitters which either prime for and activate or inhibit sexual desire and sexual arousal. These drives originate from the chemistry of our biological selves and are sensitive to ever-changing neurobiological processes. They are affected by external environmental conditions (through classical conditioning) or by the internal physiological environment (including various mood and emotion states) and can fluctuate hourly, monthly, and more subtly over the lifespan. The classical conditioning processes relate to automatic associations the brain establishes with pleasure and pain, and which involve automatic physiological and behavioural responses, rather than ideas-related responses, and so are included under this umbrella. And although subjective ideas and perceptions can emerge from various mood or emotion states, the source of the idea or perception in such instance is the physiological event itself. Furthermore, genetic predispositions (including temperament) and diseases (such as diabetes, polycystic ovarian disease, and various psychiatric illnesses) as well as events such as traumatic brain injury58 may also play a role at this neurobiological level. I refer to the prevailing collection of drives sourced from the biological system as the Biological Drive Profile, or BDP.
But we are as motivated by ideas as we are by hormones and conditioning, perhaps more so.59 Although the source is different from physiological imperatives, the result of both is the energising and directing of sexual behaviour. And so we come to the second drive source, governed by ‘supernatural’ laws, whose collection of drives I refer to as the Subjective Drive Profile, or SDP. This second drive source comprises drives that derive from ideas, beliefs, meanings, memories, values, perceptions and decisions apprehended by the subjective self — critical components of the evolving mind map that orients the subjective self.60 These meanings and ideas include those relevant to the expression of the inner self, and those relevant to a person’s role in wider society. Some of these drives are relatively stable, although changes in circumstance may cause the profile to fluctuate. Although these meaning-based drives can generate emotions (and therefore activate physiological processes), in such cases the source of the drive is not the emotion itself, but the idea or perception giving rise to the emotion.
Ideas relate to an intangible and unmeasurable dimension, yet play a critical role in the physical world of tangible and measurable events. Consider how an architect’s thoughts ultimately shape a building, or how the coach’s ideas influence the movement of players in the field. The physiological event of hormonal release and the subjective event of ideas and meanings can occur simultaneously, one activating the other, just as multiple ideas can reflect complex associations; and all of these interact. The latter are difficult to explicate, depending largely on introspection and self-awareness. Through introspection, people are generally able to identify at least some reasons that contribute to the way they might behave: for example, why they might be attracted to (or repelled by) another person. Identifying underlying belief systems and emotional responses also give clues to the drives that comprise a person’s SDP, as we will see.
The differentiation and labelling of drives in the SDP is inherently problematic, however. The brain is associative in nature,61 and so drives based on subjective perceptions will reflect meaning clusters that vary from one person to the next. And so I do not conceive the different drives as representing discrete categories or entities that mean the same thing from one person to the next: rather, I describe approximate and interdependent motivational themes, referencing motives and drives described by other theorists. These drive themes comprising meanings clumped together by association, representing various emotional62 and social needs, perceptions, attitudes, hopes and desires. Some drive themes relate more to the relational needs of the desirer and are less discriminative of the qualities of the desired one, while other drive themes are more discriminative, focusing more on the attributes of the object of desire. Some drive themes are more strongly related to sexual desire and/or arousal, while other drive themes relate more to broader emotional, social, or even practical considerations relating to interpersonal attraction and pairing. Interpersonal sexual attraction is shaped by the particular mix and prevailing ascendancy of drives in a person’s drive profile. Any one person’s drive profile is unique to that person, although various themes and trends will emerge that are common to groups of people. This drive profile changes over time, depending on personal and environmental circumstances, and on normal developmental processes.
The two sources, one essentially biological in nature, the other related to the perceptions and attributions of the subjective self, are governed by different laws and principles. Yet they interrelate, each finding context in the other, each informing the other. It may be fair to say that sexual arousal and sexual desire have more to do with the BDP, while interpersonal attraction and pairing, relating to subjective and social events, have more to do with the SDP. Nevertheless, the BDP and the SDP interact, so that the subjective self seeks to make meaningful attributions to the emotions, moods, and general experiences emerging from neuroendocrine activity, while patterns of neurochemical activation and neuroendocrine fluctuations respond to subjective perceptions. We will discover that the sexual relationship encompasses a complex mix of these drives which need to be integrated so that interpersonal attraction, sexual desire, and sexual arousal become aligned. The subjective self interacts with both drive sources, playing a critical role in the interpretation of meanings, choice of focus, and the behavioural decisions that result in the unique patterns of sexual behaviour and relationships entered into. In the process, it seeks internal consistency through minimising internal conflict, while also minimising external conflicts.
Features of the biological (BDP) and subjective (SDP) drive profiles
We have seen how ‘sexual’ has to do with the respective sexes, the sexual act, and the intentions and behaviours leading to the sexual act. But we have also seen how complex sexual behaviour is — in the factors that make it sexual,
