Dennis (1940) studied about children’s walking by Hopi race of Red Indian American children.
(G.1) Samples of 63 babies were brought up since they were born in the cradle board for 9 months with no moving as were tightly clothes wrapped.
(G.2) Samples are 42 babies were treated with freely movement as usual living with the same length of time as G1
Results showed; both groups were able to walk when they were about 14.95-15.07 months