Four Routes of Cognitive Evolution

Cecilia Heyes

ELSE / UCL

Joint ELSE / ABC Workshop “Exploring the Boundaries of Rationality”,London, 19-20 June 2003

Natural selection changes rules and representations

or

Developmental selection

or

Input processes

Source Locus

Extension

Naturalselection

Developmentalselection

Rules & reps Input process

LOCUS

SOURCE

Phylogeneticconstruction

Phylogeneticinflection

Ontogeneticconstruction

Ontogeneticinflection

Labels

Heyes (in press) Four routes of cognitive evolution. Psychological Review.

Stomach example

Enzymes= rules & reps

Foods= input process

Natural selectionNew enzymes > higher fitness

(Phylogenetic construction)

Developmental selectionProliferation with use,

loss with disuse(Ontogenetic construction)

Natural selectionNew jaw > higher fitness

(Phylogenetic inflection)

Developmental selectionIngestion > strength > more & better food

(Ontogenetic inflection)

Types of Evidence

Natural selection

• Poverty of the stimulus

• Genetically heritable

Developmental selection

• Wealth of the stimulus

• Not genetically heritable

Adaptive character

Neural localisation

Examples of ‘other’ routes

• Face processing

• Theory of mind

• Imitation

Face processing

Distinctive rules / reps - configural processing Neonatal face preference

Farah et al (1998) Psych Rev, 105, 482-498

BUT Neonatal effect subcortical

Ontogenetic construction

Gautier et al (2000)Nat. Neuro., 2, 568-573

Configural processing of other stimuli

Invariant development

Autism is heritable

Theory of mind

Distinctive rules / representations - reps of mental reps

Phylogenetic or Ontogenetic Construction

Karin-D’Arcy & Povinelli (2002) IJCP, 15, 21-54

BUT • Hearing-impaired / siblings• Nonhuman primates

BUT • Problems more general• Earliest in joint attention

• Neonatal evidence in question

• Learning models now available

Imitation

Innate mechanism with distinctive rules / reps ?

Anisfeld (1996) Dev. Rev, 16, 149-161

Ontogenetic inflection

Open Open CClose Open I

Open Close IClose Close C

TEST

Heyes, Bird & Haggard (in prep)

370

380

390

400

410

420

430

440

450

RT

ms

18 ms

C I

Can learning counteract automatic imitation ?

24 hrs

Open Open CClose Open I

Open Close IClose Close C

TEST

Open CloseClose Open

TRAINING

432 trials (6 x 72)

Open OpenClose Close

GROUP

Incompatible

Compatible

RT

ms

320

340

360

380

400

420

440

Comp IncompCC I I

34 ms 9 ms

Conclusion

• There are at least two sources and two loci of evolutionary change affecting cognitive processes

• It is possible that few adaptive characteristics of cognition are ‘adaptations’

Why describe developmental selection as ‘evolutionary’ ?

• Optional • Historical accident that VSR first identified at genetic level • Doesn’t make all cognitive change evolutionary

Information acquisition without systematic change to input or mechanisms (e.g. fact learning)

Changes to input and/or mechanism that are neutral or delecterious wrt fitness

Why not ascribe all adaptive effects of LD&C to natural selection ?

• Some not ‘foreseen’ by natural selection when LDC mechanism phylogenetically constructed

e.g. serrated finger nails

• In these cases ascription to natural selection non-discriminative / non-explanatory, like appeal to ‘laws of physics’