Peter Molenaar, Ph.D.

Professor of Human Development

113 Henderson Building

863-8373
pxm21@psu.edu

Research

The general theme of my work concerns the application of mathematical theories to solve substantive psychological issues. Some specific elaborations of this theme are the following.

1. An important aim of Psychology is to describe, explain and guide processes occurring at the level of individual subjects. I have proven that the appropriate methodology required for realizing this aim has to be based on person-specific analyses of intra-individual variation, i.e., time series analysis. The new person-specific methodology is being applied to a variety of psychological processes, including mother-child interaction, personality development, and cognitive aging. Additional applications to individual psycho-therapeutic processes and person-specific brain imaging are in preparation.

2. An important feature of person-specific methodology is the possibility to apply state-of-the-art engineering techniques, in particular computational control theory, in order to optimally guide learning and developmental processes as well as disease processes. Applications of control theory to patient-specific optimal treatment of diabetes type I and asthma patients are in progress.

3. Additional applications of mathematical theories to solve substantive psychological issues in my work include a) the use of artificial neural networks to investigate nonlinear epigenetic processes, b) innovative structural equation modeling techniques to analyze longitudinal data, and c) the use of nonlinear dynamical models of developmental stage transitions.

Programs

THEIL: A FORTRAN Program for Robust Covariance Matrix Estimation

Program Manual (.pdf file)

EKFIS0: First version of the EKFIS source code for parameter estimation in time-varying state-space models

Source Code (.txt file)

Education

University of Utrecht

B.A. * 1972 Psychology
B.A. 1976 Philosophical Logic
M.A. * 1976 Mathematical Psychology
M.A. * 1976 Psychophysiology
Ph.D. 1981 Social Sciences

* cum laude

Professional Experience

1970-1976: Research Assistant, Department of Psychology, University of Utrecht

1976-1985: Assistant Professor of Psychology, Department of Psychology, University of Amsterdam

1985-1993: Associate Professor of Psychology, University of Amsterdam

1993-1996: Professor of Developmental Psychology, University of Amsterdam and The Pennsylvania State University

1996-1998: Professor of Developmental Psychology, University of Amsterdam, Head of Department of Cognitive Developmental Psychology

1999-2001: Professor of Mathematical and Developmental Psychology
University of Amsterdam, Head of Methodology Department and Head of Department of Cognitive Developmental Psychology

2001- 2005: Professor of Psychological Methodology, Mathematical Psychology and Psychometrics, University of Amsterdam, Head Methodology Department

2005-Present: Professor of Human Development, Department of Human Development and Family Studies, The Pennsylvania State University

Publications (recent)

Molenaar, P.C.M., & Campbell, C.G. (2009). The new person-specific paradigm in psychology. Current Directions in Psychology, 18(2), 112-117.

Molenaar, P.C.M., Sinclair, K.O., Rovine, M.J., Ram, N., & Corneal, S.E. (2009). Analyzing developmental processes on an individual level using non-stationary time series modeling. Developmental Psychology, 45(1), 260-271.

Molenaar, P.C.M. (2008). [Review of the book The changing role of the embryo in evolutionary thought: Roots of evo-devo.] Twin Research and Human Genetics, February, 100-102.

Molenaar, P.C.M. (2008). Consequences of the ergodic theorems for classical test theory, factor analysis, and the analysis of developmental processes. In: S.M. Hofer & D.F. Alwin (Eds.), Handbook of cognitive aging. Thousand Oaks: Sage, 90-104.

Molenaar, P.C.M. (2008). On the implications of the classical ergodic theorems: Analysis of developmental processes has to focus on intra-individual variation. Developmental Psychobiology, 50, 60-69.

Molenaar, P.C.M., & Campbell, C.G. (2008). Discussion of the special issue on growth models for longitudinal data in educational research. Educational Research and Evaluation, 14, 377-390.

Molenaar, P.C.M., & Nesselroade, P.C.M. (2008). The recoverability of P-technique factor analysis (to appear in Multivariate Behavioral Research).

Burgess, R.L., & Molenaar, P.C.M. (2007). Evolutionary theory and the social sciences. Brain and Behavioral Sciences, 30, 20-21.

Hamaker, E.L., Nesselroade, J.R., & Molenaar, P.C.M. (2007). The integrated state-space model. Journal of Research in Personality, 41, 295-315.

Kelderman, H., & Molenaar, P.C.M. (2007). The effect of individual differences in factor loadings on the standard factor model. Multivariate Behavioral Research, 42, 435-456.

Molenaar, P.C.M. (2007). Developmental systems theory contra developmental behavior genetics: Gilbert Gottlieb, in memoriam. European Journal of Developmental Science, 2, 138-144.

Molenaar, P.C.M. (2007). Psychological methodology will change profoundly due to the necessity to focus on intra-individual variation. Integrative Psychological and Behavioral Science, 41, 35-41.

Molenaar, P.C.M., van Rijn, P., & Hamaker, E. (2007). A new class of SEM model equivalences and its implications. S.M. Boker & M.J. Wenger (Eds.), Data analytic techniques for dynamical systems. Lawrence Erlbaum Associates, 189-211.

Visser, I., Raijmakers, M.E.J., & Molenaar, P.C.M. (2007). Characterizing sequence knowledge using on-line measures and hidden Markov models. Memory & Cognition, 35, 1502-1517.

Molenaar, P.C.M. (2006). The future of dynamic factor analysis in psychology and biomedicine. Bulletin de la Société des Sciences Médicales Luxembourg, 142, 201-213.

Molenaar, P.C.M. (2006). Normative issues in psychometrics. In: L. Smith & J. Vonèche (Eds.), Norms in human development. Cambridge: Cambridge University Press, 211-219.

Molenaar, P.C.M. (2006). Psychophysical dualism from the point of view of a working psychologist. Erkenntnis, 65, 47-69.

Grasman, R. P. P. P., Huizenga, H. M., Waldorp, L. J., Böcker, K. B. E. & Molenaar, P. C. M. (2005). Stochastic maximum likelihood mean and cross-spectrum structure modelling in neuro-magnetic source estimation , Digital Signal Processing , 15(1), 56-72.

Hamaker, E.L., Dolan, C.V., & Molenaar, P.C.M. (2005). Statistical modeling of the individual: Rationale and application of multivariate stationary time series analysis. Multivariate Behavioral Research, 40, 207-233.

Molenaar, P.C.M. (2005). Rejoinder to Rogosa’s commentary on ‘A manifesto on psychology as idiographic science’. Measurement, 3, 116-119.

Molenaar, P. C. M., & Van der Maas, H. L. J. (2005). Commentary on: "Piaget's stages: the unfinished symphony of cognitive development" by D. H. Feldman. New Ideas in Psychology, 22, 249-253.

Rovine, M. J., Molenaar, P. C. M. (2005). Relating Factor Models for Longitudinal Data to Quasi-Simplex and NARMA Models. Multivariate Behavioral Research , 40(1), 83-114.

Van Rijn, P.W., & Molenaar, P.C.M. (2005). Logistic models for single-subject time series. In L.A. van der Ark, M.A. Croon & K. Sijtsma (Eds.), New developments in categorical data analysis for the social and behavioral sciences (pp. 125-145). Mahwah, NJ: Erlbaum.

Wagenmakers, E. J., Grasman, R. P. P. P., & Molenaar, P. C. M. (2005). On the Relation Between the Mean and the Variance of a Diffusion Model Response Time Distribution, J. Math. Psychol. 49(3), p. 195-204.

Wagenmakers, E. J., Molenaar, P. C. M., Grasman, R. P. P. P., Hartelman, P. A. I., & van der Maas, H. L. J. (2005). Transformation invariant stochastic catastrophe theory. Physica D, 211, 263-276.

Waldorp, L. J., Huizenga, H. M., Nehorai, A., Grasman, R. P. P. P., & Molenaar, P. C. M. (2005). Model selection in spatio-temporal electromagnetic source analysis. IEEE Transactions on Biomedical Engineering, 52 (3), 414-420.

Dolan, C.V., Wicherts, J.M., & Molenaar, P.C.M. (2004). A note on the relationship between the number of indicators and their reliability in detecting regression coefficients in latent regression analysis. Structural Equation Modeling, 11, 210-216.

Grasman, R.P.P.P., Huizenga, H.M., Waldorp, L.J., Böcker, K.B.E., & Molenaar, P.C.M. (2004). Frequency domain simultaneous source and source coherence estimation with an application to MEG. IEEE Transactions on Biomedical Engineering, 51 (1), 45-55.

Molenaar, P.C.M. (2004). A manifesto on Psychology as idiographic science: Bringing the person back into scientific psychology, this time forever. Measurement, 2 (4), 201-218.

Molenaar, P.C.M. (2004). Forum discussion of the manifesto's aggregation act. Measurement, 2 (4), 248-254.

Molenaar, P.C.M. (2004). Voorwoord. In V. Busato, Weg met Piet Vroon (pp. 11-2). Amsterdam: Amsterdam University Press.

Nesselroade, J.R., & Molenaar, P.C.M. (2004). Applying dynamic factor analysis in behavioral and social science research. In D. Kaplan (Ed.), The Sage handbook of quantitative methodology for the social sciences (pp. 335-344). Thousand Oaks, CA: Sage.

Raijmakers, M.E.J., & Molenaar, P.C.M. (2004). Modeling developmental transitions in adaptive resonance theory. Developmental Science, 7 (2), 149-157.

Van Beijsterveldt, C.E.M., Verhulst, F.C., Molenaar, P.C.M., & Boomsma, D.I. (2004). The genetic basis of problem behavior in 5-year-old Dutch twin pairs. Behavior Genetics, 34 (3), 229-242.

Hamaker, E.L., Dolan, C.V., & Molenaar, P.C.M. (2003). ARMA based SEM when the number of timepoints T exceeds the number of cases N: Raw data Maximum Likelihood. Structural Equation Modeling, 10 (3), 352-379.

Mellenbergh, G.J., Adèr, H.J., Baird, D., Berger, M.P.F., Cornell, J.E., Hagenaars, J.A.P., & Molenaar, P.C.M. (2003). Conceptual issues of research methodology for the behavioural, life and social sciences. The Statistician, 52, Part 2, 211-218.

Molenaar, P.C.M. (2003). State space techniques in structural equation modeling: Transformation of latent variables in and out of latent variable models.

Molenaar, P.C.M., Huizenga, H.M., & Nesselroade, J.R. (2003). The relationship between the structure of interindividual and intraindividual variability: A theoretical and empirical vindication of Developmental Systems Theory. In U.M. Staudinger & U. Lindenberger (Eds.), Understanding human development: Dialoques with lifespan psychology (pp. 339-360). Dordrecht: Kluwer Academic Publishers.

Molenaar, P.C.M., & Newell, K.M. (2003). Direct fit of a theoretical model of phase transition in oscillatory finger motions. British Journal of Mathematical and Statistical Psychology, 56, 199-214.

Nesselroade, J.R., & Molenaar, P.C.M. (2003). Quantitative Models for Developmental Processes. In J. Valsiner & K.J. Connolly (Eds.), Handbook of Developmental Psychology (pp. 622-639). London: Sage.

Rovine, M.J., & Molenaar, P.C.M. (2003). Estimating analysis of variance models as structural equation models. In B.H. Pugesek, A. Tomer, & A. von Eye (Eds.), Structural Equation Modeling: Applications in Ecological and Evolutionary Biology (pp. 235-280). Cambridge: Cambridge University Press.

Stauder, J. E. A., Van der Molen, M. W., & Molenaar, P. C. M. (2003). Age, intelligence, and event-related brain potentials during late childhood: A longitudinal study. Intelligence, 31 , 257-274.

Dolan, C.V., van der Maas, H.L.J., & Molenaar, P.C.M. (2002). A framework for ML estimation of parameters of (mixtures of) common reaction time distributions given optional truncation and censoring . Behavior Research Methods, Instruments, & Computers , 34 (3), 304-323.

Hamaker, E.L., Dolan, C.V., & Molenaar, P.C.M. (2002). On the nature of SEM estimates of ARMA parameters. Structural Equation Modeling , 9 (3), 347-368.

Huizenga, H.M., Heslenfeld, D.J., & Molenaar, P.C.M. (2002). Optimal Measurement Conditions for Spatiotemporal EEG/MEG Source Analysis. Psychometrika, 67 (2), 299-313.

Molenaar, P.C.M. (2002). Correct Identification and Explanation of Age-Related Changes Are Always Possible. Gerontology, 48, 13-17.

Molenaar, P.C.M. (2002). Structural equation models and state-space models: Rewriting latent variables as manifest variables (preliminary title). Book written on invitation for Advanced Quantitative Techniques in the Social Sciences, Sage (to appear).

Waldorp L. J., Huizenga H. M., Grasman R. P. P. P., Böcker K. B. E., de Munck J. C. & Molenaar P. C. M. (2002). Model selection in electromagnetic source analysis with an application to VEFs , IEEE Transactions on Biomedical Engineering , vol. 49 (10), p. 1121-1129.

Houtveen, J.H., & Molenaar, P.C.M. (2001). Comparison between the Fourier and Wavelet methods of spectral analysis applied to stationary and nonstationary heart period data. Psychophysiology, 38, 729-735.

Huizenga, H.M., van Zuijen, T.L., Heslenfeld, D.J., & Molenaar, P.C.M. (2001). Simultaneous MEG and EEG source analyses. Physics in Medicine and Biology, 46, 1737-1751.

Molenaar, P.C.M. (2001). Systems Modeling. In N.J. Smelser and P.B. Baltes (Eds.), International Encyclopedia of the Social & Behavioral Sciences (pp 15423-15428). Oxford: Pergamon.

Molenaar, P. C. M., & Nesselroade, J. R. (2001). Rotation in the dynamic factor modeling of multivariate stationary time series. Psychometrika, 66 (1), 99-107.

Raijmakers, M.E.J., Dolan, C.V., & Molenaar, P.C.M. (2001). Finite mixture distribution models of simple discriminant learning. Memory and Cognition, 29, 659-677.

Rovine, M. J., & Molenaar, P. C. M. (2001). A structural equations modeling approach to the general linear mixed model. In L.M. Collins & A.G. Sayer (Eds.), New methods for the analysis of change. Decade of behavior. (pp. 67 98). Washington, DC, US: American Psychological Association. xxiv, 442 pp.

Van Baal, G.C.M., van Beijsterveldt, C.E.M., Molenaar, P.C.M., Boomsma, D.I., & de Geus, E.J.C. (2001). A genetic perspective on the developing brain: Electrophysiological indices of neural functioning in young and adolescent twins. European Psychologist, 6 , 254-263.

Van Beijsterveldt, C.E.M., van Baal, G.C.M., Molenaar, P.C.M., Boomsma, D.I., & de Geus, E.J.C. (2001). Stability of genetic and environmental influences on P300 amplitude: a longitudinal study in adolescent twins, Behavior Genetics, 31, 533-543.

Waldorp, L.J., Huizenga, H.M., Dolan, C.V., & Molenaar, P.C.M. (2001). Estimated Generalized Least Squares Electromagnetic Source Analysis Based on a Parametric Noise Covariance Model. IEEE Transactions on Biomedical Engineering, 48 (6), 737-741.

Garst, H., Frese, M., & Molenaar, P. C. M. (2000). The temporal factor of change in stressor-strain relationships: A growth curve model on a longitudinal study in East Germany. Journal of Applied Psychology, 85 (3), 417-438.

Grasman R. P. P. P., Molenaar P. C. M. & Huizenga H. M. (2000). Coherence: A critique. Journal of Psychophysiology , vol. 14 (4), p. 261.

Molenaar, P. C. M., & van der Maas, H. L. J. (2000). Neural constructivism or self-organization? Behavioral and Brain Sciences, 23 (5), 783-784, 791-792.

Molenaar, P. C. M., & Raijmakers, M. E. J. (2000). A causal interpretation of Piaget's theory of cognitive development: Reflections on the relationship between epigenesis and nonlinear dynamics. New Ideas in Psychology, 18 (1), 41-55.

Molenaar, P. C. M., & Raijmakers, M. E. J. (2000). A phase transition between localist and distributed representation. Behavioral and Brain Sciences, 23 (4), 486.

Rovine, M. J., & Molenaar, P. C. M. (2000). A structural modeling approach to a multilevel random coefficients model. Multivariate Behavioral Research, 35 (1), 51-88.

Visser, I., Raijmakers, M. E. J., & Molenaar, P. C. M. (2000). Confidence intervals for hidden Markov model parameters. British Journal of Mathematical and Statistical Psychology, 53 (2), 317-327.

Molenaar, Peter C. M. (1996). THEIL A FORTRAN Program for Robust Covariance Matrix Estimation. The Methodology Center Technical Report Series #96-5, Pennsylvania State University, University Park, PA