If you guys ever read my previous posts on cognitive science, then you are probably acquainted with Jerry Alan Fodor and his contributions to its rise after the decline in popularity of radical behaviorism due to Chomsky’s strawman and some arguments by Lashley that have nothing to do with radical behaviorism at all.
Today we will talk a bit about philosopher of cognitive science Jerry Fodor and his notion of modularity, as well as the way this theory of modularity was taken by John Tooby and Leda Cosmides, founders of the evolutionary psychology tradition in the 90s.
Fodor and the modularity of mind
A module, according to Bermúdez (2014), is a lower-level cognitive process that works quickly to provide rapid solutions to highly specific problems. Modular systems are generally held to have most, if not all, of the following characteristics.
- Domain-specificity. They are highly specialized mechanisms that carry out a very specific job with a fixed field of application.
- Information encapsulation. In performing this job modular systems are unaffected by what is going on elsewhere in the mind.
- Mandatory application. They respond automatically to stimuli of the appropriate kind. They are not under any executive control.
- Fast. They transform input into output quickly enough to be used in the on-line control of action.
- Fixed neural architecture. It is often possible to identify determinate regions of the brain associated with particular types of modular processing.
- Specific breakdown patterns. Modular processing can fail in highly determine ways.
Again, none of these features are necessary; modularity ought degrees to admit. These characteristics are not defining (Frankenhuis & Ploeger, 2007). Also, in his critique of Tooby and Cosmides (we are talking about them below), he usually focused on two features: domain-specificity and information encapsulation, which seem to be the most important for him.
Although Fodor spoke of a modular mind, his idea of the mind was that of general-purpose programs called central processes with only modular systems in the periphery. The purpose of these peripheral modules was to process sensory input, while higher-order cognition, such as reasoning, is executed by central processes.
Computationalism
According to the computational theory of mind, the mind is a computer of sorts (Samuels, 1998). Samuels explains that “the brain takes sensorily derived information from the environment as input, performs complex transformations on that information, and produces either data structures (representations) or behavior as output.”
Note (skip if you want): If you have seen my previous posts on radical behaviorism, you will see that behaviorists think both of data structures and behavioral outputs as processes and, in general, as behaviors. There are no mental states but mental behaviors. This is sort of like a process philosophy, while in computationalism and cognitive science in general we see the mental as states with given properties that can change from time to time. This reminds me of Northoff’s (2018) distinction of process philosophy, and property philosophy of mind.
Finally, according to computationalism, the brain is made of lots of distinct computational devices or modules. This differs from early views about the mind as a general-purpose computer.
The Santa Barbara School of evolutionary psychology
Bolhuis et al. (2011) speak of Tooby and Cosmides as the pioneers of the Santa Barbara School of evolutionary psychology. The main tenet of the Santa Barbara School is that the mind is massively modular. Also, the mind is understood as an information-processing device that can be described in computational terms (computationalism), consisting of a large number of special-purpose systems (modules), which have been shaped by natural selection to perform specific functions or to solve information-processing problems that were important in the environment in which our hominid ancestors lived-the environment of evolutionary adaptation (EEA).
The massive modularity hypothesis (MMH) states, basically, that the mind consists of a large collection of functionally specialized mechanisms, or evolved modules, which are neurocognitive mechanisms specialized for solving particular adaptive problems that recurrently faced our hominid ancestors over evolutionary time.
Modularity. Fodor vs. Tooby and Cosmides
Although Tooby and Cosmides speak of modules in their MMH, their notion of module differs from that of Fodor’s. Let’s look here at the differences:
- Fodor: They are information-processing mechanisms. These mechanisms lie in the periphery of the mind, and work only processing environmental stimuli. They are domain-specific and their information is always encapsulated. One module does not interfere with another. Their main features are information-encapsulation and domain-specificity.
- Tooby and Cosmides: They are information-processing mechanisms that have been shaped by natural selection over time. They are, then, biological adaptations. These mechanisms are richly structured and functionally organized, and natural selection is the only known evolutionary process capable of generating complex, functional designs in organisms. In this case, modules can be highly interconnected and distributed across the brain. Their main feature is functional specialization, not isolation.
Here we see that there is a great difference between Fodor’s idea of modules and Tooby and Cosmides’ one. For Fodor, there are only a small set of modules in the periphery of the mind, while for the Santa Barbara School of evolutionary psychology the mind is a set of hundreds, if not thousands of modules (Evans & Zarate, 2012).
The main arguments for the MMH
Carruthers’ biological argument
According to Carruthers (2006), complex functional systems are built up out of assemblies of sub-components. He states that:
“Each of these components is constructed out of further sub-components and has a distinctive role to play in the functioning of the whole, and many of them can be damaged or lost while leaving the functionality of the remainder at least partially intact”
Carruthers (2006).
From this idea about biological systems (such as genes, cells, cellular assemblies, organs, organisms, and multi-organism units), he argues that, by extension, we should expect it to be true of cognition. Later in his book, he argues that:
- Biological systems are designed systems, constructed incrementally.
- Such systems, when complex, need to have massively modular organization.
- The human mind is a biological system and is complex.
- So, the human mind will be massively modularly in its organization
The engineering argument
Frankenhuis & Ploeger (2007) group the main arguments that were used by evolutionary psychology to develop the massive modularity hypothesis, which lies as the foundation of evolutionary psychology.
The first one is the engineering argument, according to which engineering considerations provide reasonable grounds for expecting domain-specific specialization in the human mind because functionally specialized mechanisms can be fine-tuned for fast and effective processing, while domain-general mechanisms cannot.
If there is an adaptive problem that can be solved either by a domain general or a domain specific mechanism, which design is the better engineering solution and, therefore, the design more likely to have been naturally selected for? (Cosmides & Tooby, 1994, p. 89)
Frankenhuis & Ploeger (2007).
Basically, selection pressures can be expected to produce specialization in cognition.
The error argument
According to this argument, learning processes require some element in the cognitive machinery that tells us whether our actions are a success or failure (Frankenhuis & Ploeger, 2007).
Tooby and Cosmides state that there is no domain-independent criterion of success or failure that is correlated with fitness [in general]. The reason for this is that “what counts as fit behavior differs markedly from domain to domain.” Hence, we should expect different domains with different criteria of success and failure to guide the organism’s behavioral outputs and production of data structures.
The poverty of stimulus argument (WE ARE NOT TALKING ABOUT CHOMSKY HERE)
According to evolutionary psychology’s version of the PoS argument (first developed by N. Chomsky), it is impossible in principle to learn some abilities or knowledge during a single lifetime (such as that incest avoidance is adaptive), independently of environment, because to achieve this would require observing relationships that emerge only over generations. Hence, the mind could not function as adaptively as it does without being richly and intricately structured (Frankenhuis & Ploeger, 2007).
The combinatorial explosion argument
I think this is, alongside Carruthers’ biological argument, my favorite one.
With each degree of freedom added to a system, or with each new dimension of potential variation added, or with each new successive choice in a chain of decisions, the total number of alternative possibilities faced by a computational system grows with devastating rapidity.
Frankenhuis & Ploeger argue that domain-specific architectures have the capacity to deal with explosions of possibilities for behavioral outputs and the production of data structures. This is because they contain cognitive structures that can organize information, such as:
- Domain-specific databases
- Domain-specific decision rules, and
- Rules that constrain the inputs into a system.
In contrast, a domain-general system lacks such structure. Hence, it has to assess all possible alternatives it can define. These alternatives increase exponentially as the problem complexity increases and so we have the frame problem, or combinatorial explosion problem.
Conclusions
Since biological systems, even the smallest ones such as prokaryotic cells, are built up out of assemblies of sub-components, we should expect the mind, which is a biological system, to be made of assemblies of sub-components as well by extension. This leads us to the idea of massive modularity, which is also supported by the engineering argument, the error argument, the poverty of stimulus argument, and the combinatorial explosion argument.
A massively modular mind consists of a large collection of functionally specialized mechanisms, or evolved modules. These are neurocognitive mechanisms specialized for solving definite adaptive problems that recurrently faced our hominid ancestors over evolutionary time.
Some of these modules are the social exchange module, the kin detection module, the face recognition module, the mating strategies module, the emotion detection module, the spatial abilities module, the language module, and the number module.
This hypothesis is the foundation of the Santa Barbara School of evolutionary psychology, pioneered by Tooby and Cosmides.
So far, I do not know if I agree with the Santa Barbara School as a whole because I don’t know enough about it yet. Nonetheless, from a property philosophy perspective, I do believe that the mind is massively modular. Carruthers’ biological argument and the combinatorial explosion argument are the most compelling for me.
What do you think about this? Let me know in the comments section. And, once again, thanks for reading me!
References
Bermúdez, J. L. (2014). Cognitive science. An introduction to the science of the mind. 2nd edition
Bolhuis, J. J., Brown, G. R., Richardson, R. C., & Laland, K. N. (2011). Darwin in mind: New opportunities for evolutionary psychology
Carruthers (2006). The architecture of the mind
Evans, D., & Zarate, O. (2012). Evolutionary psychology. A graphic guide
Frankenhuis, W. E., & Ploeger, A. (2007). Evolutionary psychology versus Fodor. Arguments for and against the massive modularity hypothesis
Lundie, M. (2019). Systemic functional adaptedness and domain-general cognition: broadening the scope of evolutionary psychology
Northoff, G. (2018). The spontaneous brain. From the mind-body to the world-brain problem
Samuels, R. (1998). Evolutionary psychology and the massive modularity hypothesis
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