The research aims to provide data on gender-related psychological impact of GH (Growth Hormone)treatment. Implicit measurable psychological metrics of the therapy outcome on males are to be evaluated in a Prospective Randomized Controlled Trial. As a secondary axis of the study, the investigators aim to provide descriptive documentation of the unique distress signal manifestation implicitly shown by Idiopathic Short Stature (ISS) boys and suggest methods of early detection and measurement of such manifestations that can be used to cement guidelines for the treatment in GH.

Study Design:

A prospective randomized, double blind, placebo controlled trial design, comparing four research groups, with 4 repeated psychological measures (before treatment, after 3 months,after 1 year, and at the end of treatment, after 4 years).

The study will be divided into two segments:

Segment 1:double blind, placebo controlled, will include the first 60 ISS (Idiopathic Short Stature)recruited patients. Patients in this segment will be randomized to one of the growth hormone treatment groups in a ratio of 2:1. 40 patients will be treated 4 years with GH and 20 patients will be treated with placebo at the first year of the study and will have the option to start GH treatment after one year, for a duration of 3 years.

Segment 2:after the enrollment to segment 1 will end, enrollment to segment 2 will begin.Participants in segment 2 (patients with ISS and short stature) will serve as control groups and therefore will not be treated with growth hormone. Patients in Segment 2 will be evaluated only once.

The 4 repeated psychological evaluations (before treatment,after 3 months, after 1 year, and at the end of treatment, after 4 years)will include the following:

1. Implicit Association Test
2. Masculine Self Image
3. Pictures Projective Test
4. The Rosenberg Self Esteem Scale-a self report measure of explicit self- esteem
5. Quality of Life Questionnaire
6. Silhouette Apperception Technique (SAT)- a self report measure assessing children's and adolescent's perception of their own body size compared with that of their age-related peers
7. Child Behavior Checklist

Inclusion Criteria:

1 Segment 1 :Boys at the age range of 8-13 years 2. Segment 2: Boys at the age range of 12-17 years 3. Tanner stage 1 (segment 1 only) 4. more than 2 SD's (standard deviation) below the average height

Exclusion Criteria:

1. Mental retardation,
2. Psychiatric illness,
3. Lack of informed consent\assent.
4. Health status that required chronic treatment with steroids