These are my topic notes from the text (Gomez, 2004) with my comments usually indicated by JL. (3/08/12)

new terms include prosopagnosia, heterochrony (and related neoteny, paedomorphic), intelligent, mosaic evolution, co-evolution and synergy.

1.   Hands, faces, and infancy: origins of primate minds

This book is about the process of development of primate minds – and its evolution.

A.  the primate family tree

A clever use of primate hands to show relationships p.10

primate hands

B.  Major features of primates Fig  1.3

1.    Frontal, forward facing eyes

a)   Binocular vision – depth

b)   Color

c)    Brain reorganization for these eyes

2.    Grasping limbs – esp forelimbs

Grasp rather than claws or hooks.

Both grasping and vision allow access to more tree foods

Food manipulation and acquisition a key to primate life

Human (and other) adaptations – opposable thumb requires longer thumb than apes.

Use of the human "pinky" finger enables control of held objects, throwing, weapons, stone chipping, etc. (JL See


"The primate hand is an organ specialized in having a general function-- grasping -- useful for a variety of of adaptive purposes." p.13


This is a very important point-- we type or throw fastballs or play the piano as a result of the early arboreal, insect grabbing activities of the first primates. Other mammals specialize in their forelimbs via genetic regulation (compare elephants, bats, dolphins, and humans). Primates retain the fetal form of their forelimbs much more than do the other mammals. Tool use is a consequence of these generalized graspers!


(JL Read about the utility of the human "pinky" finger.)



a)   Brain reorganization for these forelimbs

And any specific adaptations, e.g. hind limbs in orangs vs. humans, grasping tails vs. non-.

3.    Bigger brains

4.    Prolonged infancy

5.    Behavioral flexibility (consider synergy with other features)

6.    Complex social life

C.  The evolution of a world of objects

1.    Development of primate brains

a)   > Overall size

Maybe greater memory, finer grain flexible movements

b)   Mosaic evolution within

(1)  >neocortex
(2)  > vision
(3)  >hand, manipulable limbs
(4)  <olfaction

2.    co-evolution of brain, limbs, senses, ways of representing the world

"I (Gomez) will argue that manipulative behaviors co-evolved with a number of cognitive skills whose main function is to analyze and depict the world in terms of objects – not only detecting and perceiving objects as environmental units, but also detecting and using the relations between objects in space and their causal links." P.14

D.  the evolution of faces: a society of individuals

The face serves to identify and express.  Connected with vision, faces are an important element in understanding primate life.

(prosopagnosia, reduced sensitivity to facial cues in autism JL)

Primates evolved more differentiated facial musculature – apes and humans have the most complex network of facial muscles of the animal world. P.15


(JL Yet the larger apes have remarkably little voluntary control over their vocal tracts.)

1.    Other social issues

a)   Bonds and aggression

b)   Grooming and social structure

E.   Evolution of infancy

Primates remain juveniles for a very long time relative to other mammals. And there are differences among primates.

This enables each generation to acquire distinct skills from their mothers (usually) and not be inflexibly governed by genetics.

(JL, recall concepts of neoteny and paedomorphic)

1.    development mediated by parents

JL we have seen this in all the videos to date –mom carries her single offspring, with maybe a few near adolescents nearby.


"The infants' discovery of the physical and social worlds takes place from the secure base provided by the mothers.' 19

JL the concept of 'attachment' comes from this primate characteristic.)

2.    > behavioral and cognitive flexibility

Prolonged development enables flexible approaches to learning.

a)   The case of species recognition

This is a feature of all sexually reproducing species – it must be reliable or the species wonÕt exist.  Behavioral and sensory cues are important, as are early experiences that 'fix' the species based on those with mother and other relatives.  It usually works!  (But in birds it happens in a narrow time frame that can be disrupted as Lorenz demonstrated with his geese.)


(JL) So is it a big surprise that apes raised as humans tend not to reproduce? I don't think so. Did Mr Kasasi have more than a "smooch" in mind with Julia?

b)   The great importance of representations

'My argument is that a crucial characteristic of primates is their ability to construct representations of the physical and social world and mediate their behavior by means of those representations. 21'

F.   representations, development, and evolution

1.    implicit representations and practical intelligence

"the term 'representation' is fundamental in current cognitive and developmental psychology.  IT refers to the ways in which brains are capable of picking up, storing, and manipulating information about the environment"

2.    implicit vs explicit knowledge

JL This gets us into the issue of consciousness...

3.    Comparing human minds with other minds

JL this goes even more into tough issues – consciousness, language and its advantages, -- along with the mess of issues surrounding the idea of 'intelligence.'

a)   Precursors or co-cursors?

Gomez makes an important point here – we don't inherit things from existing apes (or the other way around.)  Precursors are in common ancestors – not contemporary cousins.  So it is a very questionable practice to say, for example, apes using gestures to communicate is a 'precursor' to human language.  Maybe apes inherited the precursor and we see it in their behavior, but more likely they evolved those gestures for their own use and recovery of the precursor is guesswork on the part of human scientists today.

G.  Nature, nurture, and evolutionary developmental psychology

Where do the apparent similarities and differences among species of primates come from?

(JL Look to mutations, environments, and natural selection-- especially involving heterochrony.)

2.   Ch. 2 Perceiving a world of objects

(JL The major problem with this chapter is the focus exclusively on vision – to the neglect of the other senses – hearing, smell, touch, taste,-- and the 'sixth sense'–Proprioception We may talk about this soon.)

A.  spotting objects

1.    attending to new things

See Fig 2.1
Monkeys observed to be spending more time watching more complex visual objects. They also try to touch those objects as if they know diverse sensory information corresponds to the same object.
(JL- curiosity has long been seen as a “motive” for primates. Harry Harlow contrasted monkeys with rats and pigeons on this dimension. He also studied the developmental conditions that determine these exploratory behaviors.)
Yet it is important to not overlook other sensory dimensions – e.g. smell for dogs who will spend lots of time sniffing complex (to them) odors. Many species if not all probably have some exploratory curiosity to seek out info that may be useful in their normal environment.

2.    exploring objects as a function of experience

3.    representing scenes and events

4.    inferring objects

5.    primate and other animals' ways of perceiving objects


"To summarize, primates; visual perception is designed for organizing the world in terms of objects.  Beyond the task of parsing scenes into their component units in the immediate environment, primates can also create more complex representations in which they keep track of individual objects by integrating spatio-temporal and featural cues, including a primitive sense of number. 48

B.  Cross-modal representations

"One object is the source of an extraordinary variety of sensations picked up by our different sensory modalities. 48"

(JL – much of the early speculation and research was bogus for various reasons.  Gomez reviews some of this in more detail than is perhaps necessary, given his neglect of the other senses.)

"The conclusion of these studies with human and other primates appears to be that one crucial, and probably hard-wired feature of the primate brain is the ability to put together information from different modalities into cross-modal representations of object and events... a trend already present in mammalian brains. 53"

C.  contemplating objects and events

(JL Primates are curious about objects and not just for immediate food satisfaction.)

Exploration itself appears to be an important motive in the regulation of primate behavior..54

Dunbar (2000) suggests that this improvement (from just 'contemplating' a box with goodies in it) could be attributed to some form of 'mental rehearsal' of the actions to be performed.' 56 Think of this as a kind of "priming" of possible actions.

D.  the world of objects

This early organization of perception around the unit of objects may be broadly similar across species of monkeys and apes, including humans..57

'Objects as units of perception, far from being a ready made adaptive feature of primates, are developmental products obtained under relatively constrained developmental recipes.57'

(JL- I guess this means, at least, that the animals require a certain amount of experience with objects in order to become competent at using them.  This is usually the price clever animals pay for being flexible or as we shall call it soon, 'intelligent.')


Gomez concludes that humans and apes, but not monkeys or other animals attain complete Piagetian object permanence including correct performance in the displacement task.72