Waldmann, Michael R.

Curriculum Vitae

Current Research Projects

The focus of our research is on higher-level cognitive processes including learning, reasoning, categorization, judgment and decision making. Currently we study how causal and moral knowledge is acquired, represented, and used. Methodologically we combine computational modeling with behavioral experimentation to gain insights into the cognitive processes underlying these key competencies. I am also interested in the neural basis of causal and moral reasoning, and in cognitive behavioral research comparing humans with other species.

Current research grants

Agents and causes: Reconciling competing theories of causal reasoning (DFG project; since 2011)

The psychology of moral dilemmas (DFG project; since 2010)

Causal Bayes nets as psychological models of reasoning (DFG projekt; 2005-2011)

Current Ph.D. students

Jana Samland

Simon Stephan

 

Current Post Docs

Ralf Mayrhofer

Jonas Nagel

Alexander Wiegmann

Teaching

I currently offer courses about cognitive science, in particular higher-level cognition, in the bachelor and master programs.

Affiliations

Prof. Dr. M. Waldmann wurde zum Vorsitzenden des Fachbeirats des Max-Planck-Instituts für Bildungsforschung, Berlin, ernannt.
  • American Psychological Association
  • Association for Psychological Science
  • Cognitive Science Society
  • Deutsche Gesellschaft für Psychologie
  • Deutscher Hochschulverband
  • Psychonomic Society

Editorial Boards

  • Psychological Review, Editorial Board (since 2015)

  • Journal of Experimental Psychology: Learning, Memory, and Cognition, Associate Editor (since 2010)
  • Experimental Psychology, Consulting Editor (since 2010)
  • Journal of Experimental Psychology: Learning, Memory, and Cognition, Consulting Editor (2002-2010)
  • Memory & Cognition, Consulting Editor (2006-2009)

Selected Publications

  • Samland, J., & Waldmann, M. R. (in press). How prescriptive norms influence causal inferences. Cognition.
  • Waldmann, M. R. (in Druck). Kategorisierung und Wissenserwerb. In J. Müsseler & M. Rieger (Hrsg.). Allgemeine Psychologie (3. überarbeitete Auflage). Berlin: Springer Verlag.
  • Dwyer, D. M., & Waldmann, M. R. (in press). Beyond the information (not) given. Representation of stimulus absence in rats (Rattus norvegicus). Journal of Comparative Psychology.
  • Mayrhofer, R., & Waldmann, M. R. (in press). Sufficiency and necessity assumptions in causal structure induction. Cognitive Science.
  • Waldmann, M. R. (Ed.)(in press). Oxford Handbook of Causal Reasoning. New York: Oxford University Press.
  • Waldmann, M. R., & Mayrhofer, R. (2016). Hybrid causal representations. The Psychology of Learning and Motivation (pp. 85-127). New York: Academic Press.
  • Mayrhofer, R., & Waldmann, M. R. (2016). Causal agency and the perception of force. Psychonomic Bulletin & Review, 23 (3), 789-796. Full text
  • Nagel, J., & Waldmann, M. R. (2016). On having very long arms. How the availability of technological means affects moral cognition. Thinking & Reasoning, 22, 184-208. Full text
  • Wiegmann, A., Samland, J., & Waldmann, M. R. (2016). Lying despite telling the truth. Cognition, 150, 37-42. Full text
  • Samland, J., Josephs, M., Waldmann, M. R., &  Rakoczy, H. (2016). The role of prescriptive norms and knowledge in children’s and adults’ causal selection. Journal of Experimental Psychology: General, 145, 125-130. Full Text
  • Rakoczy, H., Behne, T., Clüver, A., Dallmann, A., Weidner, S., & Waldmann, M.R. (2015). The side-effekt in children is robust and not specific to the moral status of action effects. PLoS ONE, 10(7). Full text
  • Samland, J., & Waldmann, M. R. (2015). Highlighting the causal meaning of causal test questions in contexts of norm violations. In D. C. Noelle, R. Dale, A. S. Warlaumont, J. Yoshimi, T. Matlock, C. D. Jennings & P. P. Maglio (Eds.), Proceedings of the 37th Annual Conference of the Cognitive Science Society. Austin, TX: Cognitive Science Society. Full text
  • Mayrhofer, R., & Waldmann, M. R. (2015). Agents and causes: Dispositional intuitions as a guide to causal structure. Cognitive Science, 39, 65-95. Full text
  • Samland, J., & Waldmann, M. R. (2014). Do social norms influence causal inteferences. In P. Bello, M. Guarini, M. McShane & B. Scassellati (Eds.), Proceedings of the 36th Annual Conference of the Cognitive Science Society (pp. 1359-1364). Austin, TX: Cognitive Science Society. Full text
  • Meder, B., Mayrhofer, R., & Waldmann, M. R. (2014). Structure induction in diagnostic causal reasoning. Psychological Review, 121 (3), 277-301. Full text
  • Mayrhofer, R., & Waldmann, M. R. (2014). Indicators of causal agency in physical interactions: The role of the prior context. Cognition, 132, 485-490. Full text
  • Wiegmann, A., & Waldmann, M. R. (2014). Transfer effects between moral dilemmas: A causal model theory. Cognition, 131, 28-43. Full text
  • Waldmann, M. R., & Hagmayer, Y. (2013). Causal reasoning. In D. Reisberg (Ed.), Oxford Handbook of Cognitive Psychology (pp. 733-752). New York: Oxford University Press. Full text
  • Schloegl, C., Waldmann, M. R., & Fischer, J. (2013). Understanding of and reasoning about object-object relationships in long-tailed macaques? Animal Cognition, 16 (3), 493-507.  Full Text
  • Nagel, J., & Waldmann, M. R. (2013). Deconfounding distance effects in judgments of moral obligation. Journal of Experimental Psychology: Learning, Memory, & Cognition, 39 (1), 237-252. Full text
  • Waldmann, M. R., & Wiegmann, A. (2012). The role of the primary effect in the assessment of intentionality and morality. In N. Miyake, D. Peebles, & R. P. Cooper (Eds.), Proceedings of the 34th Annual Conference of the Cognitive Science Society (pp. 1102-1107). Austin, TX: Cognitive Science Society. Full text
  • Nagel, J., & Waldmann, M. R. (2012). Force dynamics as a basis for moral intuitions. In N. Miyake, D. Peebles, & R. P. Cooper (Eds.), Proceedings of the 34th Annual Conference of the Cognitive Science Society (pp. 785-790). Austin, TX: Cognitive Science Society. Full text
  • Lewandowsky, S., Palmeri, T. J., & Waldmann, M. R. (2012). Introduction to the special section on theory and data in categorization: Integrating computational, behavioral, and cognitive neuroscience approaches. Journal of Experimental Psychology: Learning, Memory, and Cognition, 38, 803-806. Full text
  • Waldmann, M. R., Schmid, M., Wong, J., & Blaisdell, A. (2012). Rats distinguish between absence of events and lack of evidence in contingency learning. Animal Cognition, 15, 979-990. Full text
  • Waldmann, M. R., Nagel, J., & Wiegmann, A. (2012). Moral judgment. In K. J. Holyoak & R. G. Morrison (Eds.), The Oxford Handbook of Thinking and Reasoning (pp. 364-389). New York: Oxford University Press. Full text
  • Blaisdell, A. P., & Waldmann, M. R. (2012). Rational rats: Causal inference and representation. In E. Wasserman & T. Zentall (Eds.), The Oxford Handbook of Comparative Cognition (pp. 175-198). Oxford: Oxford University Press. Full text
  • Dhami, M. K., Schlottmann, A., & Waldmann, M. R. (Eds.)(2012). Judgment and decision making as a skill. Learning, development and evolution. Cambridge: Cambridge University Press.
  • Waldmann, M. R. (2012). Predictive vs. diagnostic causal learning. In N. M. Seel (Ed.), Encyclopedia of the Sciences of learning (pp. 2665-2667). Berlin, Heidelberg: Springer Verlag.
  • Waldmann, M. R. (2011). Neurath's ship: the constitutive relation between normative and descriptive theories of rationality. Behavioral and Brain Sciences, 34, 273-274. Full text
  • Mayrhofer, R., & Waldmann, M. R. (2011). Heuristics in covariation-based induction of causal models: Sufficiency and necessity priors. In L. Carlson, C. Hölscher & T. Shipley (Eds.), Proceedings of the Thirty-Third Annual Conference of the Cognitive Science Society (pp. 3110-3115). Austin, TX: Cognitive Science Society. Full text
  • Hagmayer, Y., Meder, B., von Sydow, M., & Waldmann, M. R. (2011). Category transfer in sequential causal learning: the unbroken mechanism hypothesis.Cognitive Science, 35, 842-873. Full text
  • Fenker, D. B., Schoenfeld, M. A., Waldmann, M. R., Schuetze, H., Heinze, H.-J., & Duezel, E. (2010). 'Virus and epidemic': Causal knowledge activates prediction error circuitry. Journal of Cognitive Neuroscience, 22, 2151-2163. Full text
  • Waldmann, M. R., & Wiegmann, A. (2010). A double causal contrast theory of moral intuitions in trolley dilemmas. In S. Ohlsson & R. Catrambone (Eds.), Proceedings of the Thirty-Second Annual Conference of the Cognitive Science Society (2589-2594). Austin, TX: Cognitive Science Society. Full text
  • Mayrhofer, R., Hagmayer, Y., & Waldmann, M. R. (2010). Agents and Causes: A Bayesian error attribution model of causal reasoning. In S. Ohlsson & R. Catrambone (Eds.), Proceedings of the Thirty-Second Annual Conference of the Cognitive Science Society (925-930). Austin, TX: Cognitive Science Society. Full text
  • Mayrhofer, R., Nagel, J., & Waldmann, M. R. (2010). The role of causal schemas in inductive reasoning. In S. Ohlsson & R. Catrambone (Eds.), Proceedings of the Thirty-Second Annual Conference of the Cognitive Science Society (1082-1087). Austin, TX: Cognitive Science Society. Full text
  • Nagel, J., & Waldmann, M. R. (2010). Deconfounding distance effects in moral reasoning. In S. Ohlsson & R. Catrambone (Eds.), Proceedings of the Thirty-Second Annual Conference of the Cognitive Science Society (2595-2600). Austin, TX: Cognitive Science Society. Full text
  • von Sydow, M., Hagmayer, Y., Meder, B., & Waldmann, M. R. (2010). How causal reasoning can bias empirical evidence. In S. Ohlsson & R. Catrambone (Eds.), Proceedings of the Thirty-Second Annual Conference of the Cognitive Science Society (pp. 2087-2092). Austin, TX: Cognitive Science Society.
  • Meder, B., Gerstenberg, T., Hagmayer, Y., & Waldmann, M. R. (2010). Observing and intervening: Rational and heuristic models of causal decision making. The Open Psychology Journal, 3, 119-135. Full text
  • Waldmann, M. R. (2010). Causal thinking. In B. Glatzeder, V. Goel & A. v. Müller (Eds.), Towards a theory of thinking (pp. 123-134). Berlin, Heidelberg: Springer Verlag. Full text
  • Waldmann, M. R., Meder, B., von Sydow, M., & Hagmayer, Y. (2010). The tight coupling between category and causal learning. Cognitive Processing, 11, 143-158. Full text
  • Meder, B., Mayrhofer, R., & Waldmann, M. R. (2009). A rational model of elemental diagnostic inference. In N. Taatgen, H. van Rijn, L. Schomaker & J. Nerbonne (Eds.), Proceedings of the Thirty-First Annual Conference of the Cognitive Science Society (pp. 2176-2181). Austin, TX: Cognitive Science Society. Full text
  • Griffiths, O., Mayrhofer, R., Nagel, J., & Waldmann, M. R. (2009). Causal schema-based inductive reasoning. In N. Taatgen, H. van Rijn, L. Schomaker & J. Nerbonne (Eds.), Proceedings of the Thirty-First Annual Conference of the Cognitive Science Society (pp. 691-696). Austin, TX: Cognitive Science Society. Full text
  • Blaisdell, A. P., Leising, K. J., Stahlman, W. D., & Waldmann, M. R. (2009). Rats distinguish between absence of events and lack of information in sensory preconditioning. International Journal of Comparative Psychology, 22, 1-18. Full text
  • Meder, B., Hagmayer, Y., & Waldmann, M. R. (2009). The role of learning data in causal reasoning about observations and interventions. Memory & Cognition, 37, 249-264. Full text
  • Mayrhofer, R., Goodman, N. D., Waldmann, M. R., & Tenenbaum, J. B. (2008). Structured correlation from the causal background. In Proceedings of the Thirtieth Annual Conference of the Cognitive Science Society (pp. 303-308). Full text
  • Leising, K. J., Wong, J., Waldmann, M. R., & Blaisdell, A. P. (2008). The special status of actions in causal reasoning in rats. Journal of Experimental Psychology: General, 127 (3), 514-527. Full text
  • Hagmayer, Y., & Waldmann, M. R. (2008). Zur Rolle kausaler Mechanismen beim Lernen und Denken. In S. Pauen, D. Bailer-Jones & M. Dullstein (Eds.), Mechanismen und kausales Verstehen (S. 41-58). Heidelberg: Mentis.
  • Waldmann, M. R., Cheng, P. W., Hagmayer, Y., & Blaisdell, A. P. (2008). Causal learning in rats and humans: a minimal rational model. In N. Chater, & M. Oaksford (Eds.), The probabilistic mind. Prospects for Bayesian Cognitive Science (pp. 453-484). Oxford: University Press. Full text
  • Meder, B., Hagmayer, Y., & Waldmann, M. R. (2008). Inferring interventional predictions from observational learning data. Psychonomic Bulletin & Review, 15 (1), 75-80. Full text
  • Waldmann, M. R. (2008). Kategorisierung und Wissenserwerb. In J. Müsseler (Hrsg.), Lehrbuch Allgemeine Psychologie (2. überarbeitete Aufl., S. 377-427). Heidelberg: Spektrum Verlag.
  • Reips, U.-D., & Waldmann, M. R. (2008). When learning order affects sensitivity to base rates: Challenges for theories of causal learning. Experimental Psychology, 55, 9-22. Full text
  • Waldmann, M. R. (2007). Combining versus analyzing multiple causes: How domain assumptions and task context affect integration rules. Cognitive Science, 31, 233-256. Full text
  • Hagmayer, Y., & Waldmann, M. R. (2007). Inferences about unobserved causes in human contingency learning. Quarterly Journal of Experimental Psychology, 60 (3), 330-355. Full text
  • Waldmann, M. R., & Dieterich, J. (2007). Throwing a bomb on a person versus throwing a person on a bomb: Intervention myopia in moral intuitions. Psychological Science, 18 (3), 247-253. Full text
  • Hagmayer, Y., Sloman, S. A., Lagnado, D. A., & Waldmann, M. R. (2007). Causal reasoning through intervention. In A. Gopnik & L. Schulz (Eds.), Causal learning: Psychology, philosophy, and computation (pp. 86-100). Oxford: Oxford University Press. Full text
  • Lagnado, D. A., Waldmann, M. R., Hagmayer, Y., & Sloman, S. A. (2007). Beyond covariation: Cues to causal structure. In A. Gopnik & L. Schulz (Eds.), Causal learning: Psychology, philosophy, and computation (pp. 154-172). Oxford: Oxford University Press. Full text
  • Blaisdell, A. P., Sawa, K., Leising, K. J., & Waldmann, M. R. (2006). Causal reasoning in rats. Science, 311, 1020-1022. Full text Supporting material
    Faculty of 1000 Biology evaluation: "must read"
  • Waldmann, M. R. (2006). A case for the moral organ? Book review of "Moral minds" by Marc Hauser. Science, 314, 57-58. Full text
  • Waldmann, M. R., Hagmayer, Y, & Blaisdell, A. P. (2006). Beyond the information given: Causal models in learning and reasoning. Current Directions in Psychological Science, 15 (6), 307-311. Full text
  • Hagmayer, Y., & Waldmann, M. R. (2006). Kausales Denken. In J. Funke (Hrsg.), Enzyklopädie der Psychologie "Denken und Problemlösen", Band C/II/8 (S. 87-166). Göttingen: Hogrefe. Full text
  • Meder, B., Hagmayer, Y., & Waldmann, M. R. (2006). Understanding the causal logic of confounds. Proceedings of the Twenty-Eighth Annual Conference of the Cognitive Science Society (pp. 579-584). Mahwah, NJ: Erlbaum. Full text
  • Waldmann, M. R., & von Sydow, M. (2006). Wissensbildung, Problemlösen und Denken. In K. Pawlik (Hrsg.): Psychologie (S. 217-229). Berlin-Heidelberg: Springer-Verlag. Full text
  • Waldmann, M. R., & Hagmayer, Y. (2006). Categories and causality: The neglected direction. Cognitive Psychology, 53, 27-58. Full text
  • Waldmann, M. R. (2006). Konzepte und Kategorien. J. Funke & P. A. Frensch (Hrsg.). Handbuch der Psychologie (S. 283-293). Göttingen: Hogrefe Verlag.
  • Fenker, D., Waldmann, M. R., & Holyoak, K. J. (2005). Accessing causal relations in semantic memory. Memory & Cognition, 33, 1036-1046. Full text
  • von Sydow, M., Hagmayer, Y., Metzner, N., & Waldmann, M. R. (2005). Cooperation detection and deontic reasoning in the Wason Selection Task. In: K. Opwis & I.-K. Penner (Eds.), Proceedings of KogWis05. The German Cognitive Science Conference 2005. Basel: Schwabe. Full text
  • Satpute, A. J., Fenker, D., Waldmann, M. R., Tabibnia, G., Holyoak, K. J., & Lieberman, M. (2005). An fMRI study of causal judgments. European Journal of Neurosciences, 22, 1233-1238. Full text
  • Meder, B., Hagmayer, Y., & Waldmann, M. R. (2005). Doing after seeing. In B. G. Bara, L. Barsalou, & M. Bucciarelli (Eds.), Proceedings of the Twenty-Seventh Annual Conference of the Cognitive Science Society (pp. 1461-1466). Mahwah, NJ: Erlbaum. Full text
  • Waldmann, M. R., & Walker, J. M. (2005). Competence and performance in causal learning. Learning & Behavior, 33, 211-229. Full text
  • Waldmann, M. R., & Hagmayer, Y. (2005). Seeing versus doing: Two modes of accessing causal knowledge. Journal of Experimental Psychology: Learning, Memory, and Cognition, 31, 216-227. Full text
  • Hagmayer, Y., & Waldmann, M. R. (2004). Seeing the unobservable - Inferring the probability and impact of hidden causes (pp. 523-528). Proceedings ot the Twenty-Sixth Annual Conference of the Cognitive Science Society. Mahwah, NJ: Erlbaum. Full text
  • Waldmann, M. R., Renkl, A., & Gruber, H. (2003). Das Dreieck von Begabung, Wissen und Lernen. In W. Schneider & M. Knopf (Hrsg.), Entwicklung, Lehren und Lernen. Zum Gedenken an Franz Emanuel Weinert (S. 219-233). Göttingen: Hogrefe. Full text
  • Hagmayer, Y., & Waldmann, M. R. (2002). How temporal assumptions influence causal judgments. Memory & Cognition, 30 (7), 1128-1137. Full text
  • Waldmann, M. R. (2002). Kategorisierung und Wissenserwerb. In J. Müsseler & W. Prinz (Hrsg.), Lehrbuch Allgemeine Psychologie (S. 432-491). Heidelberg: Spektrum Verlag. Full text
  • Hagmayer, Y., & Waldmann, M. R. (2002). A constraint satisfaction model of causal learning and reasoning., Proceedings of the Twenty-Fourth Annual Conference of the Cognitive Science Society (pp. 405-410). Mahwah, NJ: Erlbaum. Full text
  • Hildebrandt, M., & Waldmann, M. R. (2002). Overshadowing. In D. Janetzko, H. A. Meyer, & M. Hildebrandt (Hrsg.), Das experimentalpsychologische Praktikum im Labor und WWW (S. 223-234). Göttingen: Hogrefe-Verlag. Full text
  • Waldmann, M. R. (2002). Experimente und kausale Theorien. In D. Janetzko, H. A. Meyer & M. Hildebrandt (Hrsg.), Das experimentalpsychologische Praktikum im Labor und WWW (S. 13-42). Göttingen: Hogrefe. Full text
  • Waldmann, M. R. (2001). Predictive versus diagnostic causal learning: Evidence from an overshadowing paradigm. Psychonomic Bulletin & Review, 8, 600-608. Full text
  • Waldmann, M. R., & Hagmayer, Y. (2001). Estimating causal strength: The role of structural knowledge and processing effort. Cognition, 82, 27-58. Full text
  • Hagmayer, Y., & Waldmann, M. R. (2000). Simulating causal models: The way to structural sensitivity. In L. R. Gleitman & A. K. Joshi (Eds.), Proceedings of the Twenty-Second Annual Conference of the Cognitive Science Society (pp. 214-219). Mahwah, NJ: Erlbaum. Full text
  • Waldmann, M. R. (2000). Competition among causes but not effects in predictive and diagnostic learning. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26, 53-76. Full text
  • Waldmann, M. R., & Hagmayer, Y. (1999). How categories shape causality. In M. Hahn & S. C. Stoness (Eds.), Proceedings of the Twenty-first Annual Conference of the Cognitive Science Society (pp. 761-766). Mahwah, NJ: Erlbaum. Full text
  • Waldmann, M. R., & Martignon, L. (1998). A Bayesian network model of causal learning. In M. A. Gernsbacher & S. J. Derry (Eds.), Proceedings of the Twentieth Annual Conference of the Cognitive Science Society (pp. 1102-1107). Mahwah, NJ: Erlbaum. Full text
  • Waldmann, M. R., & Holyoak, K. J. (1997). Determining whether causal order affects cue selection in human contingency learning: Comments on Shanks and Lopez (1996). Memory & Cognition, 25, 125-134.
  • Waldmann, M. R. (1996). Knowledge-based causal induction. In D. R. Shanks, K. J. Holyoak, & D. L. Medin (Eds.), The psychology of learning and motivation, Vol. 34: Causal learning (pp. 47-88). San Diego: Academic Press. Full text
  • Waldmann, M. R., Holyoak, K. J., & Fratianne, A. (1995). Causal models and the acquisition of category structure. Journal of Experimental Psychology: General, 124, 181-206. Full text
  • Melz, E. R., Cheng, P. W., Holyoak, K. J., & Waldmann, M. R. (1993). Cue competition in human categorization: Contingency or the Rescorla-Wagner learning rule? Comments on Shanks (1991). Journal of Experimental Psychology: Learning, Memory, and Cognition, 19, 1398-1410. Full text
  • Waldmann, M. R., & Holyoak, K. J. (1992). Predictive and diagnostic learning within causal models: Asymmetries in cue competition. Journal of Experimental Psychology: General, 121, 222-236. Full text
  • Waldmann, M. R., & Weinert, F. E. (1990). Intelligenz und Denken. Göttingen: Hogrefe Verlag.
  • Waldmann, M. R., & Göttert, R. (1989). Response bias in below-chance performance: Computation of the parametric measure ß. Psychological Bulletin, 106, 338-340. Full text

Ad hoc reviews

 

  • Biotechnology and Biological Sciences Research Council
  • Brain Research
  • Deutsche Forschungsgemeinschaft (DFG)
  • Deutsche Gesellschaft für Psychologie
  • Economic & Social Research Council
  • German-Israeli Foundation for Scientific Research & Development
  • National Science Foundation (NSF)
  • Psychological Bulletin

 

  • Acta Psychologica
  • Behavioral and Brain Sciences
  • Behavior Research Methods, Instruments, and Computers
  • Canadian Journal of Psychology
  • Cognition
  • Cognitive Development
  • Cognitive Psychology
  • Cognitive Science
  • Educational Psychologist
  • Erkenntnis
  • Evolution and Cognition
  • Experimental Psychology
  • J. of Exp. Psych.: Animal Behav. Proc.
  • Journal of Exper. Psychology: General
  • Journal of Experimental Psychology: Learning, Memory, and Cognition
  • J. of Experimental Social Psychology
  • J. of Personality and Social Psychology
  • Kognitionswissenschaft
  • Learning & Behavior
  • Learning and Motivation
  • Memory & Cognition
  • Methods of Psychol. Research – Online
  • Minds and Machines
  • Perceptual and Motor Skills
  • Perspectives on Psychological Science
  • Proceedings of the Conference of the Cognitive Science Society
  • Psychologica Belgica
  • Psychological Reports
  • Psychological Research
  • Psychological Review
  • Psychological Science
  • Psychonomic Bulletin & Review
  • Quarterly Journal of Exper. Psychology
  • Science
  • Thinking and Reasoning
  • Trends in Cognitive Sciences
  • Zeitschrift für Entwichklungspsychologie und Pädagogische Psychologie
  • Zeitschrift für Psychologie