1. A science of cognition needs falsifiable theories
Although the target article's final seven theses (sect. 8) include suggestions we find promising, they are presented as vague speculation, rather than as a formal theory that makes falsifiable predictions. It is thus nonsensical to construe them as superior to a falsifiable theory on the grounds that that theory has been falsified. Every theory is certain to make some predictions that are empirically inadequate, but the appropriate response within a science of cognition is to improve the theory and not to take refuge in the safety of unfalsifiable speculation. Insightful speculation is vital – not because speculation can replace formal theorizing, but because speculation can be sharpened to become formal theory. Theory and speculation are simply not empirically comparable.
2. In a theory of cognition, a universal principle is a property true of all human minds – a cog-universal – not a superficial descriptive property true of the expressions of all languages – a des-universal
This is why generative grammar, with its explicit goal of seeking cog-universals, has always been more central to cognitive science than linguistic typology, which only speaks to des-universals. Unlike descriptive linguistic typology, generative grammar merits a central place in cognitive science because its topic is cognition and its method is science – falsifiable theory formulation.
3a. Counterexamples to des-universals are not counterexamples to cog-universals
The des-universals of Evans & Levinson's (E&L's) Box 1 must not be confused with the cog-universals sought by generative grammar. This general point applies to all cases addressed in their article, but we only illustrate with one example. That Chinese questions do not locate wh-expressions in a different superficial position than the corresponding declarative sentence (Box 1) is a counterexample to a wh-movement des-universal but, famously, generative syntax has revealed that Chinese behaves like English with respect to syntactically determined restrictions on possible interpretations of questions; this follows if questions in both languages involve the same dependency between the same two syntactic positions, one of them “fronted.” In English, the fronted position is occupied by the wh-phrase and the other is empty, whereas in Chinese the reverse holds (Huang Reference Huang1982/1998; Legendre et al. Reference Legendre, Smolensky, Wilson, Barbosa, Fox, Hagstrom, McGinnis and Pesetsky1998). It is the syntactic relation between these positions, not the superficial location of the wh-phrase, that restricts possible interpretations. Such a hypothesized cog-universal can only be falsified by engaging the full apparatus of the formal theory – it establishes nothing to point to the superficial fact that wh-expressions in Chinese are not fronted.
3b. There are two types of cog-universals: Architectural and specific universals
The former specify the computational architecture of language: levels of representation (phonological, syntactic, semantic, etc.) data structures (features, hierarchical trees, indexes, etc.), operations (rule application, constraint satisfaction, etc.). The authors correctly recognize these as “design features” of human languages, but erroneously exclude them from the set of relevant universals. These architectural universals do not yield falsifiable predictions regarding typology, but they yield falsifiable predictions regarding language learnability. For instance, Peperkamp et al (Reference Peperkamp, Le Calvez, Nadal and Dupoux2006) showed that without architectural universals regarding phonological rules, general-purpose unsupervised learning algorithms simply fail to acquire the phonemes of a language. The latter, specific universals, are tied to particular formal theories specifying in detail the architecture's levels, structures, and operations, thus yielding falsifiable predictions regarding language typology.
4a. Optimality Theory (OT), mentioned in the target article as a promising direction, contains the strongest architectural and specific universals currently available within generative grammar
According to OT's architectural universals (Prince & Smolensky 1993/2004; Reference Prince and Smolensky1997), grammatical computation is optimization over a set of ranked constraints. This strong hypothesis (more than the hypothesis of “parameters”) has contributed insight into all levels of grammatical structure from phonology to pragmatics, and has addressed acquisition, processing, and probabilistic variation (the website http://roa.rutgers.edu hosts more than 1,000 OT papers). In a particular OT theory, specific universals take the form of a set of constraints (e.g., C1=“a sentence requires a subject”; C2=“each word must have an interpretation,” etc.) A grammar for a particular language is then a priority ranking of these constraints. For instance, C1 is ranked higher than C2 in the English grammar, so we say “it is raining,” although expletive “it” contributes nothing to the meaning; in Italian, the reverse priority relation holds, making the subjectless sentence “piove” optimal – grammatical (Grimshaw & Samek-Lodovici Reference Grimshaw, Samek-Lodovici, Barbosa, Fox, Hagstrom, McGinnis and Pesetsky1998).
4b. OT's cog-universals yield theories of cross-linguistic typology that generally predict the absence of des-universals
Each ranking of a constraint set mechanically predicts the possible existence of a human language. OT therefore provides theories of linguistic typology that aim, as rightly urged by the target article, to grapple with the full spectrum of cross-linguistic variation. OT makes use of a large set of specific universals (i.e., constraints), but because of the resolution of constraint conflict through optimization, these do not translate into des-universals: In the preceding example, C1 is violated in Italian, and C2 in English. Some des-universals can, however, emerge as general properties of the entire typology, and can be falsified by the data (as, perhaps, the existence of onsetless languages). This does not entail abandoning the Generative Linguistics program, nor the OT framework, but rather, revising the theory with an improved set of specific universals.
5. Language is more a biological trait than a cultural construct
The authors do not provide criteria to determine where language is located on the continuum of bio-cultural hybrids. Lenneberg, quoted in the target article, presented four criteria for distinguishing biological traits from cultural phenomena (universality across the species, across time, absence of learning of the trait, rigid developmental schedule) and concluded that oral (but not written) language is a biological trait (Lenneberg Reference Lenneberg, Fodor and Katz1964). The validity of this argument is ignored by the authors. Ironically, OT is more readily connected to biology than to culture: the archictural-universals of OT are emergent symbolic-level effects of subsymbolic optimization over “soft” constraints in neural networks (Smolensky & Legendre Reference Smolensky and Legendre2006); and Soderstrom et al. (Reference Soderstrom, Mathis, Smolensky, Smolensky and Legendre2006) have derived an explicit abstract genome that encodes the growth of neural networks containing connections implementing universal constraints.
