Psyche Cattell
Psyche Cattell (August 2, 1893-April 1989) was an American psychologist who studied cognitive development in children. She was Chief Psychologist at Lancaster Guidance Clinic in Lancaster, Pennsylvania from 1939-1963. She published a book on intelligence testing and established a nursery school in her home which operated from 1941 to 1974. She is best known for the Cattell Infant Intelligence Scale, a downward extension of IQ testing used to assess children's development. It primarily assesses motor control and also verbalisation. Later researchers have found that the test is poorly predictive but that "low scores on the scale appear to have greater predictive validity than high scores, particularly when the child has an unfavourable medical history or an impoverished social environment." She wrote a book, Raising Children with Love and Limits, based on her experiences in 1972.

She began her education at Sargent School of Physical Education, and later attended Cornell University and obtained her master's degree, and later Harvard University for her Master of Education degree and her Doctorate in Education. Cattell also served as an instructor mental testing for the nursery training school of Boston.  During this time, she began performing research for her book, The Measurement of Intelligence of Infants and Young Children, and was led to develop better ways to evaluate brain development in infants.  She made significant improvements to the Stanford-Binet scale, an intelligence scale for young children, to form the Cattell Infant Intelligence scale, a scale which is still used today.  Cattell never married, however she adopted two children, which at the time, was incredibly rare.

Early life 
Psyche Cattell was born to James McKeen Cattell and Josephine Owen Cattell. There is not much documentation of her mother, however, her father was a famous psychologist and professor at universities such as University of Pennsylvania and Columbia University. James Cattell had a large influence on Psyche as he was very involved in his children’s education. As a professor, James Cattell had many resources to provide his children with high quality education. Cattell and her siblings were homeschooled by their father and other educators and tutors. Cattell often fell behind her siblings throughout their education, likely due to dyslexia although she was never formally diagnosed. Due to her academic struggles, her father did not support her attending college. As a result, she became a research assistant in order to save up money for college.

Academic career 
Education played a large role in Cattell's life, starting from an early age through her father.  When she earned enough tuition money, she began college at Sargent School of Physical Education, where she obtained her undergraduate degree. She went on to obtain master's degrees from both Harvard and Cornell. She was a research assistant at Harvard University, starting in 1922, and Stanford University in 1925. Her time at Harvard is what led her to further research on methods of testing infants' IQs. She went to California to work with Lewis Terman on the Stanford Achievement Test and the development of a masculinity-femininity test.

After her work at Stanford, she returned to Harvard in 1927 and became the first woman to receive a Doctor of Education from the Harvard Graduate School of Education. While working as a research assistant at Harvard she participated in and assisted with many tests regarding intelligence in children. While a research assistant, she discovered that many of these mental tests could be improved, as they pertained more to school aged children than to infants. By 1932, she was named a research fellow at Harvard and began developing a new testing method, which resulted in the Cattell Infant Intelligence Scale and was published in her book, The Measurement of Intelligence of Infants and Young Children. She was also an instructor in mental testing for the nursery training school of Boston. Throughout summers she attended many courses at institutions including Woods Hole Marine Biological Laboratory, the Mount Desert Island Biological Laboratory, and the University of Vienna.

Cattell never married, but did adopt two children.

Cattell moved to Lancaster, Pennsylvania, where her brother was living, in 1939 to become chief psychologist at the Lancaster Guidance Clinic. She spent the rest of her life in the area. She established a school for young children in her house, known as the Cattell School, in 1941, and continued to operate it after her 1963 retirement until 1974.

The Cattell Infant Intelligence Scale 
While working at Harvard, Cattell assisted with many developmental intelligence tests which revolved around the brain development of children and the impact of their environment  on it. These tests aimed to examine the ability of children aged from 2–30 months old. She derived this test from the Stanford-Binet scale and the work she did at Harvard. She identified the issue with the available tests at the time, and therefore attempted to implement a new method of testing which worked for younger children.  The goal of these tests was to analyze brain development in young children as well as identify the ways in which birth conditions affect the central nervous system. Cattell administered these tests using a variety of toys for each age group tested; each age level had five different items. She created a standardized form of testing early mental ability through these tests, administering 1,346 examinations to 274 children. The Cattell Infant Intelligence scale was considered particularly impactful because of its younger age range, short administration time, and easy scoring methods.  Cattell implemented significant changes to the test by taking into account the use of objects which may be influenced by home life, and removing them from the test in order to make the test more objective. She published her findings in her book, The Measurement of Intelligence of Infants and Young Children, and sold some kits to perform the scale commercially. The scale is useful because, while it is not able to identify specific problems in a child's development, it may catch that there is a problem early on.

Academic and professional work 
Research assistant, Harvard Growth Study, Harvard University (1922-1925)
Research assistant in Psychology under Lewis Terman, Stanford University (1925-1926)
Research Fellow, Harvard University School of Public Health (1932-1939)
Instructor in Mental Testing, The Nursery Training School of Boston (1936-1938)
Psychologist, Lebanon County Mental Health Clinic, Lebanon PA (1939-1942)
Chief Psychologist, Guidance Clinic of Lancaster, PA (1939-1963)
Maintained Private Practice (1939-1972)
Published the Cattell Infant Intelligence Scale (1940)
Founder and Director of The West End Nursery School (later renamed The Cattell School), Lancaster, PA (1941-1974)

Notable works of literature 
Psyche Cattell is the author of various books and articles:

The Eruption and Growth of the Permanent Teeth. Journal of Dental Research, 8, 279-287 (1928)
Dentition As a Measure of Maturity. (Harvard Monog. Educ. No.9). Cambridge: Harvard University Press. (1928)
The Development of Intelligence and Motor Control in Infancy. Review of Educational Research. 6, 3-16. (1936)
The Development of Motor Functions and Mental Abilities in Infancy. Review of Educational Research. 9, 5-17. (1939)
The Measurement of Intelligence of Infants and Young Children. NY: Psychological Corporation (1940)
Intelligence of Infants and Its Measurement. Transactions of the New York Academy of Science. 3,162-71. (1941)
Raising children with Love and Limits. Chicago: Nelson-Hall (1972)