Professor David Elkind (born March 11, 1931) is an American child psychologist and author. His groundbreaking books — The Hurried Child,[1] The Power of Play[2] and Miseducation[3] — informed early childhood education professionals of the possible dangers of "pushing down" the elementary curriculum into the very early years of a child's life. By doing so, he argued, teachers and parents alike could lapse into developmentally inappropriate instructional and learning practices that may distort the smooth development of learning. He is associated with the belief of decline of social markers.

David Elkind is chief scientific advisor to “Just Ask Baby” and professor emeritus of Child Development at Tufts University in Medford, Massachusetts. He was formerly professor of Psychology, Psychiatry and Education at the University of Rochester.

Elkind obtained his doctorate at UCLA and then spent a year as David Rapaport's research assistant at the Austen Riggs Center in Stockbridge, Massachusetts. In 1964–65 he was a National Science Foundation Senior Postdoctoral Fellow at Piaget's Institut d'Epistemologie Genetique in Geneva. His research has been in the areas of perceptual, cognitive and social development where he has attempted to build upon the research and theory of Jean Piaget.

David (Hebrew: דָּוִד, דָּוִיד, Modern David Tiberian Dāwîḏ; ISO 259-3 Dawid; Strong's Daveed; beloved; Arabic: داوود‎ or داود‎ Dāwūd) was, according to the Hebrew Bible, the second king of the United Kingdom of Israel and, according to the Gospel of Matthew and the Gospel of Luke, an ancestor of Jesus. David is seen as a major Prophet in Islamic traditions. His life is conventionally dated to c. 1040–970 BC, his reign over Judah c. 1010–1003 BC,^{[citation needed]} and his reign over the United Kingdom of Israel c. 1003–970 BC.^{[citation needed]} The Books of Samuel, 1 Kings, and 1 Chronicles are the only sources of information on David, although the Tel Dan stele records "House of David", which some take as confirmation of the existence in the mid-9th century BC of a Judean royal dynasty called the "House of David".

David is very important to Jewish, Christian and Islamic doctrine and culture. In Judaism, David, or David HaMelekh, is the King of Israel, and the Jewish people. Jewish tradition maintains that a direct descendant of David will be the Messiah. In Islam, he is known as Dawud, considered to be a prophet and the king of a nation. He is depicted as a righteous king, though not without faults, as well as an acclaimed warrior, musician, and poet, traditionally credited for composing many of the psalms contained in the Book of Psalms.

Jean Piaget (French pronunciation: [ʒɑ̃ pjaʒɛ]; 9 August 1896 – 16 September 1980) was a French-speaking Swiss developmental psychologist and philosopher known for his epistemological studies with children. He was the eldest son of Arthur Piaget (Swiss) and Rebecca Jackson (French). His theory of cognitive development and epistemological view are together called "genetic epistemology".

Piaget placed great importance on the education of children. As the Director of the International Bureau of Education, he declared in 1934 that "only education is capable of saving our societies from possible collapse, whether violent, or gradual."

Piaget created the International Center for Genetic Epistemology in Geneva in 1955 and directed it until 1980. According to Ernst von Glasersfeld, Jean Piaget is "the great pioneer of the constructivist theory of knowing."