WHAT MAKES YOU SUCH A TOOL USER?

Transcription

1 WHAT MAKES YOU SUCH A TOOL USER? Gedeon O. Deák Cognitive Science & Human Development

2 today s topic FOR

3 Is FOR a great (cognitive) leap forward? studies of VCAs* (Very Complex Automata: extensively debugged/beta-tested in demanding environments) Kenward et al, 2005 Boesch-Achermann & Boesch, 1993 Visalberghi & Limongelli, 1994

4 MONKEY VS. BOY!!! non-h. primates (most reports): sticks to probe, retrieve, rake food stones to crack nut [*meta-tool-use?] cups to drink leaves to sponge blades to cut tools to groom with stones to make depressions sticks/stones to fish/break insect nests leaves to rub off irritants/spines leaves as umbrellas; gloves (thorns)? sticks for walking-aids; weapons? supports (stacked) for climbing 36-month-old (1 day): bottle; cup for drinking blankets for warmth fork for eating remote control for changing channel ball for throwing bubble wand for making bubbles; tray for solution spatula (toy) for lifting food (toy) ketchup bottle (toy) for squirting strings for retrieving balloons stick for whacking brother plate for carrying food broom for sweeping crayons for drawing cup for containing crayons stuffed animal for pillow button for producing noise switch for light on/off spigot for water on/off handle for toilet flushing towel for drying soap for washing

5 Human tool-use is quantitatively unique and qualitatively unique Enculturated apes can learn new skills (sweep-with-broom, hammer, use container) BUT: 14-month-old babies learn as fast as 3- to 31-year-old apes (Orangutans did better than other apes) Buttelmann et al, 2008

6 What is the cognitive leap? cognitive ability to: create tools that amplify natural actuator functions (or create new ones) to alter our homes, acquire resources, etc.

7 Pebble chopper, Algeria, Lower Paleolithic (1.8-1 MYO) Quartzite Acheulian handaxe, Niger (.5-.2 MYO) Also: arrowheads, awls, axes, axe hammers, chisels, drills, sickles. Found in Africa, Asia, Europe, Flint Aterian bifacial blade, Northwest Africa, Middle Paleolithic (75-30 kyo) Tenerean knapped bifacial notched axe, Sahara, Neolithic (7-6 kyo) Key points: - Increasing diversity of FORs Increasing effort (# of hits ) Increasing cultural complexity (but: recent implies more preserved?) Increasing specificity of affordances Images: World Museum of Man Bronze tanged sword, Middle East (3500 yo)

8 Early hominin tool artifacts Paleolithic 2,500,000 BCE Earliest stone tools, Ethiopia 2,100,000 BCE Tanzanian stone tools 700, 000 BCE Stone tools at Abu Simbel, Nubia 400, 000 BCE Cave Drawings of animals at Ethiopia (unconfirmed) 250, 000 BCE Numerous stone artifacts in Nubia and Egypt Late Paleolithic / Neolithic 75,000 BCE Shell Jewelry (Blombos Cave, South Africa) 35,000 BCE Decorated ostrich egg shells (Namibia) 26,000 BCE Painted stone slabs (Namibia) 16,000 BCE Domestication of grasses (Ethiopia) 8000 BCE Boat (Northeast Nigeria)...and beyond

9 Hominin tool-use entwined with culture Apes (maybe not monkeys) have tool-using cultures that are: passed down in a way (via opportunity) without credible evidence of teaching So what are the conditions for developing a material culture?

10 ...but also dependent on cognitive - specifically, representational - capacity "Action according to rules begins to be determined by ideas, not by objects... It is terribly difficult for a child to sever thought [by which he means a habitual representation or symbol] from object. Play is a transitional stage in this direction. At that critical moment when a stick i.e., an object becomes a pivot for severing the meaning of horse from a real horse, one of the basic psychological structures determining the child s relationship to reality is radically altered" - Lev Vygotsky ( )

11 Origins of tool use? Expecting cause-effect relations in infancy: (Leslie & Keeble, 1987) Social learning / teaching Zukow-Goldring & Arbib, 2008

12 Level 1: Learning function-types What affordances make [OBJECTx1...i] FOR [ACTION(X)]? Learning to use a spoon (McCarty, Clifton & Collard, 2001) Radial grip

13 Generalizing function-types months: learn non-obvious affordance, generalize to similar novel object [Baldwin] months [Bauer & Dow, Bauer & Fivush] see causal sequence delay enact on new props month-olds pretend functions without props [Harris]

14 Level 2: Abstract Function Concept quickly infer properties, possibilities, classes despite conflicting/confusing information thinking flexibly about function reduces trial-and-error top-down route to infer FOR

15 Evidence of the very idea of FOR (abstract concept of function) original question: do children flexibly use shape & function? test: dissociate shape, function - Responses: match, name

16 method 3/4-year-olds shape/function object triads: ALL DIFFERENT all functions demonstrated Practice trials: clean-up suggestion: shape: put it with the one that s the same shape function: one that [does the same thing] non-specific: put it with another one Sorting: no reminders or feedback Naming: open-ended

17 Sorting: generalizing abstract rules 3-year-olds 4-year-olds

18 Evidence for the idea FOR: NO rule, reminders, feedback in test functions and forms all different to sort consistently by function, must generalize abstraction but it s not mindless focus on function other evidence of controlled selection of function info: selective function-naming (by 4.5 years) in EVERY sorting condition

19 How does function concept develop? Bloom et al: Object kind is based on intentions of its creator. Kelemen; German: Design stance Defining function as intended function Relation to Functional fixedness

20 Developing knowing about function 1.5 years: represent abstract function types by 2.5 years: quickly learn/adapt new functions by 4 years: abstract concept of function flexibly induce function-types for new object How? Fast function-type look-up table? Isolate attention to effect-specific affordances? Inhibitory processes develop from 2-5 years Isolate attention to goal-specific affordances? Mentally simulate (imagine) cause-effect events?

21 Recap: Human thought about FOR Not unique to hominin species Quantitative and qualitative amplification Not because our manual skills expand affordances Partly the teaching culture 4-year-olds generalize by shape or function, based on context 4-year-olds have an abstract concept of function per se evoked by local social input (suggestion) 4-year-olds connect function knowledge to conventional language practice (label artifacts by function)

22 Interested in research?