Table 1.

Comparison between observed motor development items in a sample of “high-potential” children followed longitudinally (n = 60) (Vaivre-Douret) [5] and French developmental standardised norms in the first two years of life [8, 9].

Items observed (Vaivre-Douret) [5]	Sample (n = 60) mean age and SD*(months, weeks)	DEF-MOT norms (Vaivre-Douret) [8] mean age and SD (months, weeks, days)	Brunet-Lézine norms revised [9] success 50%–90% (months)
Holds head in axis	1 m + 1 w	2 m 4 d + 1 m 1 d	3 m
Voluntary grasp	3 m + 1 w	4 m 10 d + 1 m 2 d	4 m
Turning overresponse	4 m + 4 w	6 m 10 d + 1 m 9 d	8 m
Sitting without support	6 m + 3 w	8 m 6 d + 1 m 2 d	10 m
Sits up alone	7 m + 3 w	8 m 24 d + 1 m 6 d	10 m
Stands up with support	8 m + 4 w	10 m 18 d + 1 m 18 d	10 m
Crawls	8 m + 3 w	10 m 12 d + 1 m 3 d	9 m
Takes bead between thumbs and forefinger	8 m + 2 w	9 m 10 d + 1 m 6 d	9 m
Independent walking	12 m + 4 w	14 m 20 d + 2 m 6 d	14 m
Start eating with a spoonon his own	12 m + 2 w	18 m 14 d + 1 m 2 d	17 m
Climbs stairs	15 m + 2 w	17 m 4 d + 1 m 10 d	—
Comes down stairs withhelp without alternating feet	16 m + 3 w	19 m 1 d + 1 m 2 d	—
Tower of at least 8 bricks	23 m + 4 w	29 m 1 d + 1 m 2 d	30 m
Climbs stairs alone without support alternating feet	24 m + 1 w	34 m 1 d + 2 m 1 d	—
Puts slippers on without help	24 m + 3 w	30 m 8 d + 1 m 5 d	30 m
Rides tricycle or bikewith stabilisers	24 m + 3 w	36 m 3 d + 1 m 1 d	—

*(Significant items (Student's t-test, liberty degree = 118), P < 0.001, compared to motor development standardised norms).