Is Reactivity all of a Piece?

Things have been might quite around the garden for a while. In an attempt to see if can’t stir up a few of the ghosts of threads past, I will engage in my favorite activity: attacking semi-compatibilism, by way of my other favorite activity, mangling science.

In Responsibility and Control, Fischer and Ravizza argue that “reactivity is all of a piece” (73); that is, if a mechanism is reactive to some incentive to do otherwise, than the mechanism is reactive to any incentive to do otherwise. This is important for the total package, because they want to draw the inference from moderate reasons-receptivity to the conclusion that given the actual incentives, the mechanism could have responded differently. Fischer believes that it is only fair to blame someone for wrongdoing if this condition is fulfilled.

Here is the argument for the claim that reactivity is all of a piece. Suppose that an agent As on the actual sequence, but were the agent presented with a strong reason against A-ing, he would get more energy or focus, and in virtue of this energy or focus he would perform some action incompatible with A-ing. In that case, Fischer and Ravizza argue, it is natural to say that were the agent presented with a strong reason against A-ing, he would act from a different mechanism to the one upon which he actually acts.

Now let’s turn to the empirical evidence. I think the available evidence shows that agents do in fact respond to reasons against default actions precisely by getting access to fresh supplies of energy. The evidence comes from studies of ego depletion; the paradigm in which self-control is apparently depleted over time, such that subjects who have engaged in one self-control task find a subsequent self-control task considerably more difficult, and persist at it for a significantly shorter length of time. These studies strongly suggest that self-control draws upon an energy source. In fact, we even know what that energy source is: it’s glucose! Drinking glucose-rich fluids can restore levels of self-control to pre-depletion levels, while drinks sweetened with artificial sweeteners don’t help at all.

Now here’s the interesting finding. When subjects are ego depleted, they are not literally at the mercy of their preponderant urges. Instead, given the appropriate incentives they can exercise self-control. Thinking about one’s close relationships or one’s values, or being reminded of one’s pre-existing intentions and even cash incentives help people successfully to exercise self-control. But these remedies are short-term; they leave the subject significantly more depleted than before.

The best explanation of this evidence, so far as I can see, is that strong reasons allow subjects to access stores of energy that would otherwise be unavailable (perhaps controlled by the same systems that regulate our perception of muscular fatigue). Ordinary exercises of self-control therefore seem to involve what Fischer and Ravizza regard as switching mechanisms (in any case, and more importantly, it seems false that we can infer from the fact that the subject would have reacted to some strong reason that their mechanism is reactive to the actual incentives).

Comments

[Dan]

Really interesting, Neil! I've been suspicious of the "all of a piece" claim for some time myself. But ever since I've begun to wean myself off of sugary beverages I've lacked the will to work out the details. Damn you Coke Zero!!

[Joe]

Interesting, but a bit quick for me. So, to help me sort this through: the phenomenon of ego depletion seems to show that rather than one mechanism reacting to inputs, some instances of self control involve switching mechanisms, right?

As long as that new mechanism is weakly reasons reactive the subject can still be morally responsible on F&R's view.

So I see why one should be worried about the inference that if the SUBJECT would have reacted to some strong reasons then their mechanism is reactive to the actual reasons, but the subject is reacting by switching mechanisms.

I would be more worried if ego depletion brought into question the inference from the mechanism being reactive to strong reasons, to the mechanism being reactive to the actual reasons. Does this make sense or am I off base here?

I think the second inference has to do with the "all of one piece" thing, and I'm not sure how ego-depletion touches it.

[Neil]

Joe,

I’m not sure I understand what you’re saying. Here’s how I see things. F&R are concerned to show that the mechanism upon which the agent actually acted was reactive to the very incentive to which it responded; they hope that the upshot of the relevant counterfactuals give them this result. The thought here, I take it, is that the flexibility exhibited has to be flexibility in nearby possible worlds, for the inference from counterfactual reaction to actual reactivity to be a good one: the fact that the mechanism would have reacted differently if the incentive had been eternal torture is not good evidence for actual reactivity. But since we’re concerned with actual reactivity, it had also better be the case that the very same mechanism is involved. Now there are two questions here: are F&R committed to the claim that counterfactual access to extra energy is inconsistent with sameness of mechanism? And is this a good test for sameness of mechanism? I’m pretty sure that the answer to the first question is ‘yes’; I take it that’s what they’re saying pp. 73-4. But it’s far from clear that the answer to the second question is ‘yes’; why shouldn’t the very same mechanism sometimes be able to tap into extra reserves of energy? There is a very deep question hereabouts: I take it that the intuition lying behind the claim that the test is a good one is the thought that were the mechanism only able to react differently if it had access to extra energy then it cannot actually react differently. The deep question is how we test for actual sequence reactivity: so far as I can see, we are back on the terrain of the conditional analysis of could have done otherwise, which we hoped to avoid all along. After all, it is common ground that given that the mechanism is deterministic, there is some sense in which the mechanism could not have reacted differently.

[Joe]

I think I see. I get the same thing out of 73-4. Tapping into extra energy reserves doesn't seem like an adequate basis to say that an agent is changing mechanims then, especially in light of this research that shows ordinary acts of self control tap into extra energy.
What are the answers that Fischer gives regarding testing for actual sequence reactivity and identifying mechanisms? I can't think of any way other than intuition.