Motor Development - Myrtle McGraw’s Twin study of Johnny and Jimmy (1930-42)

A silent movie assembled for the International Jubilee Congress of Sports Medicine, Moscow, May, 1958 Dr. Myrtle Byram McGraw (1899 - 1988) developed this film primarily for a presentation to the Congress of Sports Medicine in Moscow in May 1958. She did not intend to release the film for general distribution, but later changed her mind when audiences to whom she showed the film continued to react so enthusiastically to the opportunity to see the excerpts illustrating Johnny en Jimmy’s developmental progress across many motor tasks in a single film. All excerpts used in the film were taken from dr. McGraw’s original research film with the exception of the final section which shows Johnny and Jimmy’s movement in several tasks at age 22. Dr. McGraw wishes to request that those who use this film view the film with the understanding that these examples were selected for the purpose of illustrating the changes in the boys’ motor behavior over time but that they were selected from many hundreds of observations made during her study with the exception of those included when Johnny and Jimmy were 22. It is recommended that the viewer read or review the book ’Growth, A study of Johnny and Jimmy’ to understand the purpose of this research and the framework under which the investigated proceeded. A summary of the sequences on the film together with the reference of the reprint edition of Growth is attached. A second recommendation is that the viewer read dr. McGraw’s article written when the boys were six years of age. McGraw, M. Growth: A study of Johnny and Jimmy. New York: Appleton Century, 1935 A reprint is available from Arno Press, New York, 1975 Comment Kangmasful: I am a bit confused. Is that means that Jimmy was more talented (despite they are twins) but Johny had outperformed him by being more trained? Response betapicts . A real setback of the research was that bloodtests at older age showed that J&J were not idententical twins. However, McGraw concluded that her training could enhance specific skills (like roller skating and swimming) but did not accelerate general development, the boys started crawling, walking and talking at the same age. So she concluded that development was controlled by maturational processes. Nowadays this view is not endorsed anymore. For instance, Zelazo cs could show that exercise of the stepping- or walk-reflex did force the start of independent walking. 00:32 - I GRASPING REFLEX - Jimmy stronger than Johnny at age 1 month 01:20 - II REACHING BEHAVIOR - Jimmy more advanced than Johnny at 5 months / 7 months / 8 months 02:35 - III CREEPING - Jimmy at 7 months, Johnny at 7 months - not yet creeping 03:21 - IV SPECIAL EXERCISE ACTIVITIES for Johnny during first two years 03:26 - 1. Swimming, newborn swimming reflex (2 weeks old) / swimming practice Johnny 8 months / 11 months / 16 months 04:27 - 2. Slide climbing at 8months - 18 degr. / 10 months 42 degr. / 12 months 61 degr. / 21 months 70 degr. 06:47 - 3. Jumping at 14 months / 16 months 06:53 - 4. Climbing off pedestals at 15 months / 07:49 - 5. (Roller) skating at 12 months / Coasting on skates at 13 months / skating at 14 months / 15 months / coasting at 15 months 09:12 - 6. Walking up and down inclines at 13 months / 14 months / 15 months 10:05 - 7. Manipulating pedestals at 18 months / at 21 months 11:30 - V JOHNNY & JIMMY AT 22 YEARS (in McGraw’s backyard) 11:41 - 1. Balancing on one foot Jimmy - Johnny 11:55 - 2. Lying down, standing up, using opposite foot and hand (from supine) 12:09 - 3. Standing up from supine 12:25 - 4. Jumping down 12:38 - 5. Walking, balanced on branch 12:50 - 6. Climbing and descending a ladder Music: Respectively.: Fig Leaves Times Two, Breaktime, Batty McFaddin & Olde Timey - Kevin MacLeod ()