DRMacIver's Notebook

The Accelerator/Brake Model

The Accelerator/Brake Model

I recently read Come As You Are, a book about sexuality (primarily women’s sexuality, but it mostly works for everyone).

It is by far the most annoying book that I will nevertheless recommend. It was about 50% stuff I already knew (which I only skimmed but seemed pretty good), but the other 50% contained a lot of useful ideas that helped make sense of some things I only partially knew. It was also 100% annoying and I hated the author’s writing style. I will grant I am not in the target audience for it (it is primarily written for women), but the friend who recommended it was a woman and she also hates the writing style so I don’t think that’s why, I just think it’s objectively very annoying (especially if you’re not from the USA). Nevertheless, it was on balance very worth reading.

One thing that was particularly helpful was the brake/accelerator model for sexual arousal.

The model is very simple: There are two systems, the Sexual Excitation System (SES), the accelerator, and the Sexual Inhibition System (SIS), the brake. The SES is what turns you on, the SIS is what turns you off.

If you’re currently not interested in sex and you’d like to be, you need to understand which of these is at play: It might be that your accelerator isn’t being pushed by the current sexual context, or it might be that something is pressing hard on your brake.

Different people have different levels of sensitivity on each of the brake and accelerator. On average women have much more sensitive brakes (i.e. are much easier to turn off) and men have much more sensitive accelerators (i.e. are much more easy to turn on), but there’s a lot of individual variation.

One of the least helpful things you can do is make a mistake about which system is in play. It doesn’t help to try to turn someone on if their foot is slammed hard on the brake, and it doesn’t help to try to make someone comfortable and at ease if they’re already fine and the problem is just that the context isn’t at all arousing.

The former is particularly bad, because pressure is one of the things most likely to activate someone’s brakes, because it creates negative emotional association with the whole experience. It’s also particularly common, because people (especially people who have relatively insensitive brakes, like most guys) often don’t realise that the brake is a potential problem at all.

Since reading about the brake/accelerator model I’ve been seeing it everywhere. I think a lot of motivation is like this, where there are things that we really want to do (the accelerator is on hard) but also procrastinate hard because there’s a huge ugh field around the thing and we find it massively hard (so are the brakes) and we just end up with the gearbox in our head grinding. In the same way as with sex, trying to want to do the thing even more isn’t going to help, and treating it as an issue of motivation will just cause one to build up even more guilt and shame around the subject, making it even more aversive.

This likely also ties in to the desire and safety model of growth, where desire acts as the accelerator and a lack of safety acts as the brake (and indeed a lack of safety is often a major brake activator in a sexual context). Given the context in which I’ve been thinking about a lot of the personal growth work, it’s probably not entirely a coincidence that these track.