1. wobbles, humps and sudden jumps1 Wobbles, humps and sudden jumps. Views and methods in the study of developmental transitions and variability Paul van Geert University of Groningen

2. wobbles, humps and sudden jumps2 Wobbles, humps and sudden jumps … Exploring developmental transitions … In the context of a personal and somewhat unorthodox view on The nature of psychological variables The phenomena that we should pay attention to Based on the belief that Behavior must be explained by contextualist and dynamic theory The individual person should be the focus of our analyses Exploring developmental transitions … In the context of a personal and somewhat unorthodox view on The nature of psychological variables The phenomena that we should pay attention to Based on the belief that Behavior must be explained by contextualist and dynamic theory The individual person should be the focus of our analyses

3. wobbles, humps and sudden jumps3 Wobbles, humps and sudden jumps … We will have to address fundamental theoretical and methodological issues I shall discuss transitions over time but also transitions over descriptive dimensions (categorization) And will occasionally address issues such as the color of socks, the nature of our data sets, curve fitting and why we should not always be afraid of disagreement among observers… We will have to address fundamental theoretical and methodological issues I shall discuss transitions over time but also transitions over descriptive dimensions (categorization) And will occasionally address issues such as the color of socks, the nature of our data sets, curve fitting and why we should not always be afraid of disagreement among observers…

4. wobbles, humps and sudden jumps4 Transitions …

5. wobbles, humps and sudden jumps - transitions5 Transitions (1 of 3) A passage from one state, stage or place to another … A movement, development or evolution from one form, stage or style to another… Assumptions The passage lasts shorter than the stages (…) themselves The stages are stable … A passage from one state, stage or place to another … A movement, development or evolution from one form, stage or style to another… Assumptions The passage lasts shorter than the stages (…) themselves The stages are stable …

6. wobbles, humps and sudden jumps - transitions6 Transitions (2 of 3) Classical stage theories (Piaget) Stage transitions Are stages real? Piaget was more interested in the problem of the construction of novelty Novelty: transition from old to new How can something new arise from something old in development? 1970ies: It cannot: it must be there in advance (Chomsky, Fodor) 1990ies: Dynamic systems theory: self-organization and spontaneous increase in complexity Classical stage theories (Piaget) Stage transitions Are stages real? Piaget was more interested in the problem of the construction of novelty Novelty: transition from old to new How can something new arise from something old in development? 1970ies: It cannot: it must be there in advance (Chomsky, Fodor) 1990ies: Dynamic systems theory: self-organization and spontaneous increase in complexity

7. wobbles, humps and sudden jumps - transitions7 Transitions (3 of 3) The basic form of transitions Catastrophy theory: elementary discontinuities (van der Maas and Molenaar) Mechanisms to explain transitions Vygotsky Microgenetic studies (Siegler, Kuhn, Granott, Fischer, …) Dynamic systems theory (Thelen & Smith, vG) Dynamic skill theory (Fischer) Distributed and situated cognition The basic form of transitions Catastrophy theory: elementary discontinuities (van der Maas and Molenaar) Mechanisms to explain transitions Vygotsky Microgenetic studies (Siegler, Kuhn, Granott, Fischer, …) Dynamic systems theory (Thelen & Smith, vG) Dynamic skill theory (Fischer) Distributed and situated cognition Common theme Dynamic, time-based, process- oriented nature of psychological phenomena Common theme Dynamic, time-based, process- oriented nature of psychological phenomena