Volume 9, Number 2, 2006

IN MEMORIAM
Peter D. Eimas
Paul C. Quinn and Lynne C. Nygaard

Editor's Note
Richard N. Aslin

THEMATIC COLLECTION: INTRODUCTION

Why Primates?: The Importance of Nonhuman Primates for Understanding Human Infancy
Daniel J. Weiss and Laurie R. Santos

THEMATIC COLLECTION: ARTICLES

Cotton-Top Tamarins’ (Saguinus oedipus) Expectations About Occluded Objects: A Dissociation Between Looking and Reaching Tasks
Laurie R. Santos, David Seelig, and Marc D. Hauser

The Effect of Heterogeneity on Numerical Ordering in Rhesus Monkeys
Jessica F. Cantlon and Elizabeth M. Brannon

Self-Awareness in Human and Chimpanzee Infants: What Is Measured and What Is Meant by the Mark and Mirror Test?
Kim A. Bard, Brenda K. Todd, Chris Bernier, Jennifer Love, and David A. Leavens

Behavior of Infant Chimpanzees During the Night in the First 4 Months of Life: Smiling and Suckling in Relation to Behavioral State
Yuu Mizuno, Hideko Takeshita, and Tetsuro Matsuzawa

Mechanisms Underlying Language Acquisition: Benefits From a Comparative Approach
Daniel J. Weiss and Elissa L. Newport