Ourselves as Experience Machines
Humans do not exist alone. We are only constrained toward consciousness by other human beings (see, for more, Philippe Rochat's Others in Mind: Social Origins of Self-Consciousness). In relationships, each person has both the character of an experiencer and of an experience provider. In interactions with each other, we are each always experiencing the other and being an Experience Machine for the other. This is the core of humanity, and the reason consciousness exists.
This is particularly important in sexual relationships. There is an immediately observable divide in the nature of experiences desired in a sexual relationship between men and women; these can be seen in the variety of pornography consumed by each gender, regardless of sexual orientation. For men, the (superstimulus?) pornography consumed tends to be explicit visual imagery of sex with attractive, young women or men - a substitute first-person experience of sex. That is not what women seek out and buy; what sells to women is romance novels, explicit or not, and rather than providing a first-person experience of sex, they provide a vicarious experience of being an extremely high-value female. "Valuedness" is the pornographic heart of women's romance literature; the male lover is important to the extent to which he demonstrates and supports the value of the heroine. So men desire first-person experiences with high-value women; women desire experiences of valued-ness. (Of course, the reverse is true as well, but not to nearly the same extent, as revealed in consumption patterns and of course predicted by mating strategy theory.) We might say that women (perhaps especially those of us of Northern European extraction?) are primarily Experience Machines, and experience even ourselves as such, whereas men are primarily experiencers. Intense sexual selection has perhaps made us something like a creepy autonomous RealDoll with a womb.
In all relationships, sexual or not, each person has a dual nature: experiencer and experience provider. Each of these aspects, on each person, acts as a "selection site" - in both Darwinian and memetic senses. There are, on the one hand, experiences that humans avoid or seek out; on the other hand, there are the experiences that one provides others or protects others from. Each of these has selection effects for reproductive fitness. Both one's preference for certain experiences, and one's ability to deliver certain experiences, are relevant to one's social and mating success. To the extent that cultural items give us experiences and help us produce experiences in others, these dual natures also affect the evolution of cultural items.
As an example, the book How to Win Friends and Influence People is a cultural item that demonstrates how to be a better Experience Machine for others. In friendships as well as mating, we will be accepted or get the high-status experiences we want to a greater degree if we can give those experiences to others. This cultural item (the book) has been successful at getting itself reproduced to the extent that it helps individuals create and have the experiences that they desire from and for each other.
Both of these aspects of our dual nature allow us to exercise some (bounded) control, and to have some limited effect on them. We can, to some degree, choose what we experience; again, to a limited degree, we can choose what we cause others to experience. However, the distance between what we try to cause other to experience and what they actually experience is frequently a dark chasm of longing and misery.