Chapter 3

Social intelligence

Sets us apart at the level of individual minds and brains

* Some have argued that the main evolutionary pressure for human intellectual development is to understand and predict complex social interactions + outwitting peers → lead to more general changes in other non-social domains (toddlers excelled on this domain but not the physical one)

Culture

Sets us apart in terms of group behavior

• Shared sets of values, skills, artifacts, beliefs, and technology amongst a group of people → inherent social dimension as culture is shared amongst group members via social learning

• The differences between cultures are largely attributable to environment.

• The similarities between cultures to biology and evolution → brains developed in such a way that we can create and absorb shared knowledge, skills, and beliefs

Social learning

Transmission of skills and knowledge from person to person, within and across generations

The social intelligence hypothesis (Machiavellian)

Evolutionary pressures to be socially smarter led to general changes (brain size) resulting in increased intellect in non-social domains.

• Intelligence manifested in social life (include problem solving).

• Complex society selects for enhanced intelligence (specific characteristics) due to the need for this

  • Regarded as a more general capacity than a specialized set of functions dealing with social life

  • Don’t only select for the amount of intelligence but also for the type

Social intelligence and brain size in primates problems

• Different ways of defining SI

• Not easy to measure SI in natural settings

• Approach assumes brain size to be useful index of general intellect

Dunbar

Strong correlation between SI and brain size

• Social group size as an approximate measure of social complexity → significant correlation with neocortex ratio (larger brain = greater no. sustainable relations)

• Claimed that our brains can only support active relationships with 150 others

  • Populations above this number can be maintained by creating special roles enforcing social cohesion (police)

• Cooperation between 2 people can be maintained:

  • Within small groups.

  • Based on first-hand experience of each other’s behavior (cheating tendencies)

  • Direct and 3rd party retaliation (attacking those who attack friends)

  • Alliance formation

• Large-scale groups exist due to development of cultural rules of cooperation which people collectively agree on (legal, moral, religious norms) in addition to those based on direct experience → facilitate interactions between strangers

Reader and Laland

Suggest a co-evolution of an aspect of SI (social learning) and non-social intelligence (innovation)

• Don’t support view that social factors were more important in leading to increased intellect/brain size (both crucial)

  • Social learning is required → innovate ideas have limited impact on cultural development if they die out with creator

  • Innovation is required → being able to learn from each other is only important if it’s worth learning

• Tool use can be considered a product of both these processes

Deception

Complex social skill involving appreciation of another’s knowledge and the ability to manipulate it

Length of immaturity

Important factor going hand-in-hand with evolutionary increases in brain size

* Provides extended window for learning and adapting to environment and culture
* If intelligence is related (in part) to our ability to learn from e/o, then it is equally a product of:
* Nature (genetic disposition to learn)
* Nurture (accumulating knowledge of world)

Convergent evolution

Same evolutionary selection pressures create same outcome independently in different species

Divergent evolution

Association can be traced back to a common ancestor possessing both characteristics

Problems in considering non-primate species

Translating markers of SI across different species

* Dolphins (don’t form stabel social groups over time) and elephants have larger brains and display social intelligence
* However, animals with smaller brain sizes also display SI (hyena, bat)

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In sum, evidence from non-primates is not necessarily inconsistent with SI hypothesis but throws spotlight on potential mechanisms (selection pressures and evolved cognitive processes)

Schaik, Isler, Burkart

Larger brains come at the cost of energy expense and requires other adaptations in the organism to support this type of evolution

* However, other factors may pose limitations → high energy costs of flying in bats may limit brain growth, as well as seasonal variations in food supply

Clayton

Pattern observed in primates doesn’t necessarily hold elsewhere

* However, bigger brains linked to cooperative mating systems and longer-term monogamy → maintaining these relations requires SI resembling those seen in primate alliances

Fraser

Primates and corvids have not shared a common ancestor in ages, so the similarities in SI are taken as evidence for convergent evolution

Language evolution and SI hypothesis

Debate whether language arose from non-specific evolutionary changes or not → general selection pressures to be smarter (socially and/or cognitively), leading to general changes from which language emerged

• Dunbar: evolved due to social pressures living in large groups → enabling social cohesion

• Chomsky: arose from selection pressures relating specifically to communicative needs (so not a by-product of general changes)

Recently → language should not be considered as a single entity but is multi-faceted (production of speech, syntax, semantics, etc)

Larynx

Involved in sound production; descend in humans (cannot breathe and swallow at same time but crucial for human speech)

* Disagreement whether descend happened due to need for increased repertoire of speech or because of another reason not related to communication

Syntax

Rules by which words are combined to make meaningful sentences

* Hierarchical nature of syntactic representation may be driven by need to mentally represent complex social groups and hierarchies

Evaluation CH3

Good evidence for SI hypo → evolutionary increases in relative brain size accompanied by increased complexity in social domain (group size, deception, social learning)

• Unclear is the extent to which specific processes (language or TOM) arose out of these more general changes / were specifically shaped during course of evolution

• Future research should identify genes linked to brain growth during evolution

Evolutionary origins of culture

Human societies have different systems of culture, wherein some have developed far more advanced forms of technology than others

* Blackmore: survival of the fittest of cultural trends

Meme

Units of culture transmitted from person to person according to their own perceived fitness (benefits they convey or are believed to)

* Certain skills or ideas may be more valued by particular members → more likely to be passed on until replaced with summ else

Culture pyramid (in non-human species)

• Social info transfer: used temporarily and then discarded (keeping tabs on where other animals hide food) → mammals, birds, fish, invertebrates

• Traditions: distinctive pattern of behavior shared in group → birds would have traditions but not culture (lacking evidence)

• Culture: collection of traditions → apes and monkeys

  • Perry: capuchin monkeys showed multiple social traditions with unique distributions across capuchin communities → games are culturally learned rather than being part of innate behavioral repertoire

  • Witehead: multiple traditions constituting a culture amongst species of dolphins and wales

• Cumulative cultures: traditions are generally enhanced or modified over time (Roman to Arabic no)

  • Evidence in non-human species is controversial

    • Must involve multiple transmission episodes, through social learning, and should increase complexity or efficiency

  • Several possible mechanisms that could enable this culture

    • Degree of innovation in species, different social learning mechanisms (language, imitation), desire to cooperate and be prosocial

Imitation

Social learning based on understanding of goals, intentions, and mental states of other individuals

• Some believe only humans to be capable of this

  • Not straightforward and challenging to find ways to observe the unobservable via behavior (mental states)

• Involves understanding and reproduction of actions of others (sophisticated form of social learning)

  • Reproducing goals of someone else is likely to entail understanding of their intentions → sociocognitive mechanisms and sensorimotor mechanisms are implicated

Humans don’t need to be trained to imitate, but evidence suggests that arbitrary acts can be imitated by non-human apes with considerable training

• If human and ape imitation are cognitively equivalent (assumed), why is human imitation (and culture) more prolific?

  • Humans more creative and innovative → more things worth imitating

  • Different rewards to imitation

    • Apes → material

    • Humans → reward in itself serves to bind human social groups

Non-imitative learning

Could arise from a number of mechanisms

Mimicking

Copying the action without understanding the goal of the action

Stimulus enhancement

Having another individual draw attention to an object → increased likelihood observer engagement with object

Local enhancement

Another individual drawing attention to location increasing likelihood observer engagement with location

Contagion

Repetition of behaviors that are innate rather than learned (yawning)

Intentional stance

Tendency to explain or predict the behavior of others using intentional states (wanting, liking)

* Infants show goal-based imitation (button pressing study)

Problem linking imitation with mental states

Imitation emerges in humans during the 1st year of life, while accurate performance on most tests of reasoning about mental states emerge between 3-4 years

Evaluation 2

Natural selection through variations in the gene pool, enables species to adapt slowly to their environments

* Humans and other species also able to adapt much faster due to social learning (mechanism)
* When coupled with innovation and other cognitive skills → enables complex systems of culture which can be modified over time
* Cultural traditions expand our cognitive and physical capabilities and provide a means for establishing group and individual identities

Neuronal recycling

Neural circuits for writing and calculation appear to be quite conserved across individuals and cultures

* Neural resources may be recruited by cultural knowledge

Visual word form area (VWFA)

Brain region in the ventral visual stream responding to visual representation of letter strings → may have evolved for certain types of object recognition

Intraparietal sulcus

Region in the parietal lobes responding during arithmetic tasks and when viewing different types of numerical symbols within and across cultures

• Maybe represents core semantic representation of numbers

• May also exist in other species

  • However, humans can augment this basic ability via additional use of numerical symbols extending their numerical abilities

    • Cognition itself is transformed by the availability of certain culturally learned symbols

Extended cognition

Use of external technologies to increase cognitive capacities

* Systems of writing and number representation can be considered social in a narrow sense → invented and passed on by collective action of many minds
* However, they had more direct influences on the nature of social interactions.
* Money = means of social exchange and as a way of displaying/achieving higher social standing via consumption or benevolence.

Tools

Objects, normally hand-held, used to manipulate secondary objects

* Brains adapted to create tools and transmit this info socially
* Some have argued that cultural use of symbols and tools enables new kinds of thought
* Clark: natural born cyborgs soaking up and creating complex technologies
* Technology and ideas behind them are themselves passed and modified over time (NOT in the genes but by social and cultural transmission) → our minds and brains are transformed as a consequence

Receptive field

Region of space eliciting neuronal response

• Certain neurons in brain that respond both when a particular body part is touched and when a visual stimulus is moved near the same body part

  • Frontal and parietal regions (multi-sensory)

    • Iriki: visual receptive fields of these neurons changed as result of monkey using a tool → no longer centered on arm but elongated down length of tool (not when passively held tho)

In humans there is evidence that multi-sensory processing of space is extended by tool use

• Non-blind people show temporary brain adaptions when trained with cane

• Blind people show permanent adaptations

  • Flashes of light near hand and at end of tool → facilitate detection of tactile stimulus on the hand after tool use

  • Prior to tool use, only flash of light on or near the hand did this

Mirror neurons (intention detectors)

Response properties disregard distinction between self and other → crucial basis for imitation

• Respond to actions which are often precise and goal-directed

  • Don’t respond to mimicked action in the absence of an object or if it moves robotically without external agent → purposeful nature of action instead of visual/motoric elements

• Respond if an appropriate action is implied as well as directly observed

  • The PM (F5) area contains abstract representations of action intentions used for both planning one’s own actions and interpreting those of others

    • Umilta: neurons responding to grasping

      • Action is different but the goal is the same, and the neural response is determined by the goal

        • Enable understanding of at least 1 mental state (intentions)

Mirror neurons in the parietal lobes

Tend to be more sensitive to the wider context in which an action is situated

• Grasping action (subsequent goal eat or putting away)

• The primary motor cortex itself contains neurons with motor and visual properties but they respond to the other mechanics of particular movements rather than abstract features (goals)

• STS also responds to specific movements of body parts, but have a purely visual component which may act as input to the mirror neuron system

• Medial temporal regions

Evidence mirror neurons in humans

Human analogue of F5 is believed to be in Broca’s area (B44) extending into the premotor area

• Activated when observing hand movements (esp when imitation is required)

• Action observation biases in the primary motor area itself

Controversy mirror neurons

Regarding their functionality

* Some argue they arise via associative learning
* When we move our bodies, we see visual consequences of our actions and learn to associate action observation and execution together
* Mirror neurons aren’t necessarily genetically pre-programmed for imitation or any other function
* Others argue that mirror neurons function to predict what the consequences of actions are (how the limbs will move through space to achieve a goal) but that other regions represent the intended goals

Potential flaw mirror neurons

Assumed to be present in monkeys, chimps, and humans

* The imitation-like behavior some monkeys can perform could perhaps reflect contagion (or innate motor programs) rather than imitation based on goals
* Chimps are capable of more complex forms of imitation, but perhaps it doesn’t serve the same social functions as in humans

What is missing between species?

MN maybe necessary precursor to imitative tool use but aren’t sufficient

* Macaque monkeys can use tools in the lab but only after extensive training which involves systems of reward and gradual modification of behavior
* When tool use has been achieved, their performance is swift, effortless, and shows some degree of flexibility

The differences in the brains of macaque monkeys with acquired tool use vs. those without

Lies in the way 2 particular regions are connected

* Proficient tool-using monkeys have extra connections between the intraparietal sulcus and the temporo-parietal junction
* The intraparietal region contains neurons whose visual receptive fields are extended via tool use and also mirror neurons
* Changes in gene expression in this region accompany learning of tool use and presumably trigger the connectivity changes
* The human brain may have evolved stable connections between these 2 regions that are normally absent in many other primates
* This may enable humans to link neural mechanisms related to tool use (multi-sensory visuo-tactile neurons) with mechanisms related to social cognition (perspective taking, TOM)
* The temporo-parietal junction has been implicated when contrasting physical perspectives between self and other