In 1955, Creighton J. Hale, Associate Professor of Physiology, took a leave of absence from Springfield College to conduct research on the adolescent players of the eight teams who participated in the 1955 Little League Baseball World Series.   Professor Hale secured their chronological ages, measured their heights and weights and assessed their biological maturities.   The 1956 Research Quarterly published his findings.

     To assess the biological ages of one hundred twelve chronologically aged ten, eleven and twelve year old Little League baseball players, Professor Hale selected C. W. Crampton’s work.   Professor Hale did not state why he declined the more definitive 1950 Greulich/Pyle Radiographic Atlas of Skeletal Development of the Hand and Wrist.

     In 1900, New York City Physician C. Ward Crampton assessed adolescent male physical development to determine puberty’s onset.   Crampton concluded that pubic hair development best indicated the onset of male puberty.   Crampton described three pubic hair stages.   He explained that he created two levels to his second pubic hair stage because raters had trouble differentiating between some pubic hair and an abundance of pubic hair.   Crampton published his findings in 1908.

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| Classification |                     Description                    |
|---------------------------------------------------------------------|
| Pre-pubescent  |  No pubic hair                                     |
| Pubescent-1    |  Straight, unpigmented pubic hair                  |
| Pubescent-2    |  Straight, pigmented pubic hair                    |
| Post-pubescent |  Kinked, curled, pigmented pubic hair              |
|---------------------------------------------------------------------|

     Crampton provided the percent of thirteen and one-half, fourteen and one-half and fifteen and one-half year old males at each pubescent stage.

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|  Pubescent Stage  |     13 1/2     |     14 1/2     |     15 1/2     |
|----------------------------------------------------------------------|
| 1 (Pre-pubescent) |      51%       |      23%       |      12%       |
| 2 (Pubescent)     |      29%       |      34%       |      22%       |
| 3 (Post-pubescent)|      18%       |      42%       |      65%       |
|----------------------------------------------------------------------|

     To study variability between adolescent males’ height, weight and right hand grip strength, Crampton identified subjects by their Puberty Index.   The percent of males in a chronological age times its pubescent stage equals the ‘Puberty Index’ for that group.   For example, the Puberty Index of post-pubescent 13 1/2 year olds is fifty-four (18% x 3   =   54).   Crampton noted that post-pubescents were taller, heavier and stronger than pubescents and pre-pubescents.

     Because Marshall’s Sexual Maturation Indicator Value (SMIV) incorporates pubic hair development descriptions in much the same way as the three pubic hair stages that C. W. Crampton used, with logical deductions regarding facial and axillary hair and genitalia development, we can relate Crampton’s pubescent stages to Marshall’s Sexual Maturation Indicator Values.

     Pre-pubescent have pubic hairs that resemble the fine hair present over the remainder of their bodies.   The second pubic hair stage of Marshall’s Sexual Maturation Indicator Value reads similarly.   Axillary hair develops similarly to pubic hair, but facial hair and genitalia development lags slightly behind.   Therefore, Marshall’s Sexual Maturation Indicator Value for pre-pubescents averages 142.79 months or 11.90 years.

     Professor Hale assessed forty-two 1955 Little League Baseball World Series players as ‘pre-pubescent’.   One pre-pubescent was ten years old, twelve were eleven years old and twenty-nine were twelve years old.   These pre-pubescents averaged 12.53 chronological years old (150.36 months), 59.02 inches and 95.36 pounds.   Therefore, the Estimated Skeletal Age (ESA) of the pre-pubescents averages 142.41 months or 11.87 years.

     Pubescents have pigmented pubic hair.   The third pubic hair stage of Marshall’s Sexual Maturation Indicator Value reads similarly.   Axillary hair develops similarly to pubic hair, but facial hair and genitalia development lags slightly behind.   Therefore, Marshall’s Sexual Maturation Indicator Value for pubescents averages 155.16 months or 12.93 years.

     Professor Hale assessed nineteen 1955 Little League Baseball World Series players as ‘pubescent’.   Three pubescents were eleven years old and sixteen were twelve years old.   These pubescents averaged 12.60 chronological years old (151.20 months), 60.30 inches and 96.05 pounds.   Therefore, the Estimated Skeletal Age of the pubescents averages 151.81 months or 12.65 years.

     Post-pubescent have kinked or twisted pubic hair.   The fourth pubic hair of Marshall’s Sexual Maturation Indicator Value stage reads similarly.   Axillary hair develops similarly to pubic hair, but facial hair and genitalia development lags slightly behind.   Therefore, Marshall’s Sexual Maturation Indicator Value for post-pubescents averages 167.53 months or 13.96 years.

     Professor Hale assessed fifty-one 1955 Little League Baseball World Series players as ‘post-pubescent’.   Four post-pubescents were eleven years old and forty-seven were twelve years old.   These post-pubescents averaged 12.97 chronological years old (155.64 months), 63.20 inches and 115.54 pounds.   Therefore, the Estimated Skeletal Age of the post-pubescents averages 165.51 months or 13.79 years.

|------------------------------------------------------------------------|
| 112 Little | 3# |     Ages     |  Ave  | SMIV  |  Ht   |  Wt    |  ESA |
|  Leaguers  |    | 10 | 11 | 12 |  CA   |       |       |        |      |
|------------------------------------------------------------------------|
| Pre-Pubs   | 42 |  1 | 12 | 29 | 12.53 | 11.90 | 59.02 |  95.36 | 11.87|
| Pubescent  | 19 | -- |  3 | 16 | 12.60 | 12.65 | 60.30 |  96.05 | 12.65|
| Post-Pubs  | 51 | -- |  4 | 47 | 12.97 | 13.79 | 63.20 | 115.54 | 13.79|
|------------------------------------------------------------------------|
| Totals     |112 | 01 | 19 | 92 |
|--------------------------------|

     82% or 92 of the 1955 Little League World Series participants were 12 years old, 17% or 19 were 11 years old and 1% or 1 was 10 years old.   Professor Hale evaluated 45.5% or 51 as post-pubescent, 17% or 19 as pubescent and 37.5% or 42 as pre-pubescent.

     While pre-pubescent players averaged 12.53 chronological years old, they averaged 11.87 biological years old.   Therefore, the pre-pubescents demonstrated one year of delayed biological maturation.

     While pubescent players averaged 12.60 chronological years old, they averaged 12.65 biological years old.   Therefore, the pubescents demonstrated equated chronological and biological ages.

     While post-pubescent players averaged chronological 12.97 years old, they averaged 13.79 biological years old.   Therefore, the post-pubescents demonstrated one year of accelerated biological maturation.

     Little League Baseball, Inc. eligibility rules permit only 12 year olds and younger to participate.   Nevertheless, fifty-one 12 year old players averaged 12.97 chronological years old.   Apparently, the coaches of the 1955 Little League Baseball World Series were able to find players with birth dates close to the elimination date.

     Professor Hale analyzed who played.   He found that the coaches started 72% of their post-pubescent players.   He found that 78% of the third, fourth, fifth and sixth place batters were post-pubescent.   He found that seven of the eight starting pitchers were post-pubescent.   He found that 87.5% of the starting outfielders were post-pubescent.   Clearly, post-pubescent players dominated the 1955 Little League Baseball World Series.

     To play second base, third base and shortstop requires mastering motor skills rather than accelerated size, speed and strength.   Therefore, Professor Hale for that 58% of the starting second basemen, third basemen and shortstops were pre-pubescent of which 75% of the starting shortstops were pre-pubescents.

     Professor Hale summarized that the majority of the participants in the 1955 Little League Baseball World Series were biologically advanced of their chronological ages.   He stated that post-pubescent players were fourteen biological years old.