Human Language and Adaptation Lecture Notes

Fourth Exam Preparation

Human Adaptation of Language

  • Key Components of Language:

    • Phonemes:
    • Defined as the smallest units of sound that construct language.

  • Rules of Language:

    • Grammar and Syntax:
    • Essential for stringing words together to form thoughts and sentences.

  • Innate Language Ability:

    • Humans possess an innate sense of language. Examples can be found in Pidgin and Creole.
    • Pidgin Creation Example:
    • Slaves from different tribes created a Pidgin language with basic vocabulary in the USA.
    • The subsequent generation developed this into a full-blown language, called a Creole.
    • Nicaraguan Sign Language Example:
    • Deaf children created a Pidgin of sign language in school without formal instruction, evolving into a Creole.

  • Distinction Between Human Language and Animal Communication:

    • All animals communicate through various means (e.g., scent marking, vocalizations, bee dance).

  • Brain Structures Involved in Language:

    • Perisylvian Region and areas responsible for language:
    • Broca's Area: Associated with speech production.
    • Wernicke's Area: Involved in language comprehension.

  • Impact of Brain Damage:

    • Damage to Broca’s or Wernicke’s areas results in significant language impairment.

  • Scientific Imaging Techniques:

    • PET Scans: Used to observe brain activity associated with language during speech.

  • Genetic Influence on Language:

    • FOX P2 Gene:
    • Mutation in this gene is associated with severe language impairments in some families.

  • Animal Language Learning:

    • Parrots and apes learn rudimentary language forms (like sign language with Koko or lexigrams with some chimpanzees), but these forms are not comparable to human language complexity.

  • Linguistics:

    • The study of languages and their evolutionary dynamics.
    • Languages are akin to genetic systems, showing relationships and changes over time, similar to cladograms in genetics.

Foragers and Hunter-Gatherers

  • Definition of Foragers:

    • Hunter-gatherers who derive all food from wild resources, without farming or domesticated animals.

  • Environments of Evolutionary Adaptedness (EEA):

    • Importance: To understand adaptations, consider the environment in which they evolved.
    • Example: Traits like cravings for fat and sugar are adaptive in the context of foraging - they are valuable but hard to obtain.

  • Characterization of Warm Temperate Foragers:

    • Group Size:
    • Discussion of living arrangements and social structures within foraging groups.
    • Life History Patterns:
    • Examination of fertility, mortality, and interbirth intervals in foragers in comparison to agricultural societies.
    • Women often face deficits in food acquisition especially in youth, while post-menopausal women can contribute surplus to the group.

  • Infant and Child Rearing:

    • Nuclear Families:
    • The role of both parents in food contribution.
    • Interbirth Intervals:
    • Foragers have shorter interbirth intervals (about 3.5 to 4 years) compared to other apes (5.5 years in chimps).
    • Possible due to food support from fathers and grandparents, allowing mothers to raise multiple children simultaneously.

  • Menopause in Humans:

    • Unique among species, with implications for reproductive strategy; it poses questions about its adaptation.
    • Some theories suggest that menopause allows older women to invest in grandchildren's survival instead of having their own children, known as the Grandmother Hypothesis.
    • Evidence Discussed:
    • Older women among the Hadza produce surplus; children with maternal grandmothers have higher survival rates.

  • Human Life Cycle Theory:

    • Described in terms of energy allocation from childhood (rapid growth) to reproductive efforts and investment in offspring.
    • Conflicts between mother and offspring over resource allocation, illustrated by examples of pregnancy complications (e.g., high blood pressure, gestational diabetes).

Aging and Reproductive Strategies

  • Understanding Aging:

    • Senescence: Refers to the gradual decline of physiological functions with age.
    • Men's vs. Women's Aging:
    • Men undergo reproductive senescence concurrently with bodily aging, while women experience menopause significantly earlier.

  • Theories of Aging:

    • Antagonistic Pleiotropy:
    • Genes beneficial in youth may have adverse effects in later life (e.g., high testosterone).
    • Mutation Accumulation:
    • Weakening of natural selection with age allows harmful mutations to persist as reproductive focus diminishes.

Human Pair Bonding and Mating Strategies

  • Pair Bonds as a Human Universal:

    • Examined the mutual benefits for both partners within relationships.
    • Husbands: Gain short-term paternity assurance.
    • Wives: Might receive access to resources and mate guarding.

  • Evolutionary Predictions in Mate Choice:

    • Preferences vary: Men tend to prefer younger mates who appear healthy, while women typically prefer older men with resources for better reproductive success.

  • Variations in Mating Strategies:

    • Polygyny: Common, but primarily for wealthy men.
    • Polyandry: Seen in rare circumstances, e.g., among certain Himalayan populations.
    • Ecological Constraints: Discusses how resources affect monogamy in foraging societies.

  • Bride Wealth:

    • Discussed the economic implications of marriage, particularly in polygynous societies.

  • Infanticide and Child Abuse:

    • Addressed with caution, emphasizing the naturalistic fallacy that does not justify unethical behaviors despite evolutionary explanations.

  • Child Spacing:

    • Factors influencing spacing of births among foragers, focusing on maternal energy resources and reproductive health.

Inbreeding and Its Implications

  • Avoidance Mechanisms:
    • Discussed biological and psychological bases for avoiding inbreeding within human populations.
    • Examples include Taiwanese minor marriages and Israeli kibbutzim, which show a tendency for non-attraction among those raised together.

Cooperation and Conflict in Human Behavior

  • Optimal Foraging Theory:

    • Strategies for maximizing food searching efficiency, showing gender differences in foraging behavior (men hunting vs. women gathering).

  • Food Sharing Dynamics:

    • Mutual sharing of resources, especially meat, characterized as community behavior rather than individualistic.

  • Delayed Reciprocity:

    • Generosity leads to increased support when the giver is in need in the future.

  • Costly Signaling Theory:

    • Social dynamics where resource misallocation can demonstrate social standing.

  • The Ultimatum Game:

    • Used to illustrate fairness in resource sharing within groups, showing human sensitivity to fairness in social transactions.

Future Exam Preparation

  • Exam Format and Content:

    • Expect questions resembling previous exams.

  • Sample Questions Discussed:

    • Importance of grammatical rules in understanding language.
    • Critical comparisons between foragers and modern populations regarding reproductive traits and cycles.

  • Definitions and Concepts to Know:

    • EEA: Environments of Evolutionary Adaptiveness, significance in understanding human adaptation.
    • Examples: Foragers as a model for EEA understanding.