The evidence and arguments that Baumard brings to bear in support of this explanation for the Industrial Revolution do not uniquely distinguish it from plausible alternatives. A very simple one is that increased prosperity freed up more time for individuals to engage in innovative activity and increased the benefits from doing so. This possibility is consistent with the great bulk of the evidence adduced in support of the preference-shift explanation.
The Life History approach focuses on the effects of prosperity on the development of psychological characteristics. To focus on an alternative, set aside any shifts over time in the inherent preferences and attitudes. Instead, consider how prosperity directly affected the costs, benefits, and constraints on innovative activity for mature individuals with given psychological traits. Someone who is at the edge of starvation has little time to engage in new discoveries, and is compelled to focus on generating immediate payoffs. In contrast, just as Baumard has argued, innovation requires a short-run sacrifice of time, effort, and resources, in the hope of long-term payoffs. So greater prosperity encourages a greater focus on exploration rather than exploitation.
This explanation is very similar to Baumard's thesis, and exactly for this reason, most of the evidence adduced as confirming Life History Theory is equally consistent with the alternative explanation. But this explanation does not require that prosperity have any effect on the development of psychological traits.
To put this another way, the very same argument that justifies the Life History Theory argument – that prosperity favors the lifetime development of long-term oriented psychological traits – also suggests, even if no such effect exists, that mature individuals will find it optimal to follow long-term oriented strategies. Instead of developmentally malleable psychological traits, all that is required is that (mature) humans be responsive to costs and benefits in their environments.
Specifically, the key to the Life History Theory explanation for the Industrial Revolution is that in favorable environments (prosperity during a young sensitive period) it tends to be optimal for an organism to become developmentally disposed toward a focus on strategies that have high long-term expected payoff. In such an environment, it tends to be the case that such strategies can be followed without causing short-term disaster. But for exactly the same reason, even if prosperity had no effect on development, it increases the benefit for mature adults with given psychological traits to focus more on long-term strategies.
Baumard is aware of this issue, and explicitly addresses it in section 6.3.3 of the paper. However, it is surprising that this alternative is addressed so briefly. The evidence that Baumard adduces in favor of the Life History Theory explanation as against this alternative is limited to a single page. Baumard provides insightful discussion of the changing nature of English novels of the period, attitudes toward slavery, romantic fiction, and portraiture. But these points by no means rule out the alternative explanation that we propose here, nor, for that matter, any other theories of the Industrial Revolution.
Even if these shifts occurred for the Life History Theory reasons that Baumard proposes, it is possible that the personality changes brought about by prosperity were minor relative to the incentive effects that we propose. In particular, attitudes toward slavery, romantic fiction, and portraiture are all cultural products (as is the Industrial Revolution), and it is possible that shifts in personality were amplified more by cultural evolutionary processes more for slavery attitudes and the arts than for technological discovery and adoption.
Furthermore, it is also possible that the incentive effects in our alternative hypothesis – which directed people toward a greater focus on strategies with long-term payoffs – also affected attitudes toward slavery and artistic styles, for essentially the same reason as that which Baumard proposes. For example, consider the shift of the English novel toward a focus on long-term planning. The only difference in our possible explanation for this shift from Baumard's is that this shift, instead of deriving from a shift in people's personalities, could derive from an incentive-induced shift in people's interest and attention toward long-term strategies.
Importantly, Baumard also points out that Life History Theory empirical research has documented that many important traits, including those relating to time discounting and trust, are in part set during childhood or in utero. However, even a mature individual with fixed internal attitudes toward consumption over time (what economists call “time preference”) will follow different strategies in trading off the present with the future if the individual faces different opportunities. Someone who is prosperous can afford to save more than someone at the edge of starvation, and (more speculatively) may have a greater interest in novels about making plans for the distant future.
There are, in principle, ways in which the two explanations are distinguishable. The Life History Theory explanation suggests that what is crucial is the environment individuals experience during an early sensitive period, rather than just generalized prosperity that impinges directly upon adults, as well as juveniles. So to explore Baumard's theory more deeply, it would be valuable to develop evidence about age-specific environmental shifts and their effects.
Also, the explanation we offer is far from the only possible alternative to the Life History Theory. For example, general increase in prosperity, perhaps complemented by reduced costs of transportation or communication, can widen social networks, facilitating collaboration and recombination of ideas. This also suggests that an increase in prosperity may have a positive feedback effect.
To sum up, the Life History Theory explanation for the Industrial Revolution is plausible, and may be right, but much clearer evidence would be needed to distinguish this explanation from alternatives.
The evidence and arguments that Baumard brings to bear in support of this explanation for the Industrial Revolution do not uniquely distinguish it from plausible alternatives. A very simple one is that increased prosperity freed up more time for individuals to engage in innovative activity and increased the benefits from doing so. This possibility is consistent with the great bulk of the evidence adduced in support of the preference-shift explanation.
The Life History approach focuses on the effects of prosperity on the development of psychological characteristics. To focus on an alternative, set aside any shifts over time in the inherent preferences and attitudes. Instead, consider how prosperity directly affected the costs, benefits, and constraints on innovative activity for mature individuals with given psychological traits. Someone who is at the edge of starvation has little time to engage in new discoveries, and is compelled to focus on generating immediate payoffs. In contrast, just as Baumard has argued, innovation requires a short-run sacrifice of time, effort, and resources, in the hope of long-term payoffs. So greater prosperity encourages a greater focus on exploration rather than exploitation.
This explanation is very similar to Baumard's thesis, and exactly for this reason, most of the evidence adduced as confirming Life History Theory is equally consistent with the alternative explanation. But this explanation does not require that prosperity have any effect on the development of psychological traits.
To put this another way, the very same argument that justifies the Life History Theory argument – that prosperity favors the lifetime development of long-term oriented psychological traits – also suggests, even if no such effect exists, that mature individuals will find it optimal to follow long-term oriented strategies. Instead of developmentally malleable psychological traits, all that is required is that (mature) humans be responsive to costs and benefits in their environments.
Specifically, the key to the Life History Theory explanation for the Industrial Revolution is that in favorable environments (prosperity during a young sensitive period) it tends to be optimal for an organism to become developmentally disposed toward a focus on strategies that have high long-term expected payoff. In such an environment, it tends to be the case that such strategies can be followed without causing short-term disaster. But for exactly the same reason, even if prosperity had no effect on development, it increases the benefit for mature adults with given psychological traits to focus more on long-term strategies.
Baumard is aware of this issue, and explicitly addresses it in section 6.3.3 of the paper. However, it is surprising that this alternative is addressed so briefly. The evidence that Baumard adduces in favor of the Life History Theory explanation as against this alternative is limited to a single page. Baumard provides insightful discussion of the changing nature of English novels of the period, attitudes toward slavery, romantic fiction, and portraiture. But these points by no means rule out the alternative explanation that we propose here, nor, for that matter, any other theories of the Industrial Revolution.
Even if these shifts occurred for the Life History Theory reasons that Baumard proposes, it is possible that the personality changes brought about by prosperity were minor relative to the incentive effects that we propose. In particular, attitudes toward slavery, romantic fiction, and portraiture are all cultural products (as is the Industrial Revolution), and it is possible that shifts in personality were amplified more by cultural evolutionary processes more for slavery attitudes and the arts than for technological discovery and adoption.
Furthermore, it is also possible that the incentive effects in our alternative hypothesis – which directed people toward a greater focus on strategies with long-term payoffs – also affected attitudes toward slavery and artistic styles, for essentially the same reason as that which Baumard proposes. For example, consider the shift of the English novel toward a focus on long-term planning. The only difference in our possible explanation for this shift from Baumard's is that this shift, instead of deriving from a shift in people's personalities, could derive from an incentive-induced shift in people's interest and attention toward long-term strategies.
Importantly, Baumard also points out that Life History Theory empirical research has documented that many important traits, including those relating to time discounting and trust, are in part set during childhood or in utero. However, even a mature individual with fixed internal attitudes toward consumption over time (what economists call “time preference”) will follow different strategies in trading off the present with the future if the individual faces different opportunities. Someone who is prosperous can afford to save more than someone at the edge of starvation, and (more speculatively) may have a greater interest in novels about making plans for the distant future.
There are, in principle, ways in which the two explanations are distinguishable. The Life History Theory explanation suggests that what is crucial is the environment individuals experience during an early sensitive period, rather than just generalized prosperity that impinges directly upon adults, as well as juveniles. So to explore Baumard's theory more deeply, it would be valuable to develop evidence about age-specific environmental shifts and their effects.
Also, the explanation we offer is far from the only possible alternative to the Life History Theory. For example, general increase in prosperity, perhaps complemented by reduced costs of transportation or communication, can widen social networks, facilitating collaboration and recombination of ideas. This also suggests that an increase in prosperity may have a positive feedback effect.
To sum up, the Life History Theory explanation for the Industrial Revolution is plausible, and may be right, but much clearer evidence would be needed to distinguish this explanation from alternatives.