A researcher planned to test whether children stuttering was caused by criticism of their speech.the professor who was the principle investigator in this study believed he began stuttering when,at the age of six,a teacher told him and his parents the he had begun stuttering.he sebsequently developed a stutter that persited for the rest his life.(1)the graduate student was given a list of study participants by the orphanage ,which included information on each child.she paired the children,aged 5 to 15 yrs old,onthe basis of similarities in the age,gender,fluency,self-esteem,and IQ.she then randomly assigned one member of each pair to group 'a' and one to group 'b'.thus,30 children(15 boys and 15 girls)with an average age of 10yrs old,IQ 95,self esteem at the 90th percentile,and verbal fluency at the 80th percntile were assigned to group 'b'.for six months from january to may 1939 the female graduate met individually with each memeber of group'a'each week for 45 minutes and repeatedly told each child that his/her speech production was normal,that his/her enunciation was excellent,and complimented these children on the fluency of the their speech.during the same period in 1939,the female graduate student also met individually with each memeber of group'b'each week for 45 minutes.the members of group'b'were repeatedly told that their speech was abnormal,that they had begun to stutter,and it was imperative that they correct their speech immediately.these group'b'children were encourage to vigilantry monitor their speech-making every effort to avoid stuttering.futher,it was suggested to the children in group'b'that it might be best to remain silent if they could not speak perfectly.during these,the graduate student adhered to prepared scripts for group'a'and group'b'and made identical comments(from the second scripts)to all of the children in group'b'.during the week following the graduate students last meeting with the children,the speech production of all the children in group'a' and group'b'was independently assessed by three research assistant.these research assistants had been extensively trained to utilize a stanardized measure to rate each child and were unaware of childrens groupd memebership.the research assistant scores were compared for all'60'children and the scores assigned by the three research assistants were very similar.in addition,children's classroom teachers and staff memebers completed standardized forms assesiing each childs self-esteem and reporting any changes in the children scholl performance since since the beginning of studys.results indicated that children in group'b'the group whose speech was critized recieved lower speech production scores on the average compared to the children in group'a'.while the group'b'children did not stutter,their speech was jerky and hesitant;they spoke fewer words;and their enunciation was deficiant.the group'b'children also exhibited significantly more self-conscious behaviors while speaking(e.g.looking down,covering their eyes,fidgeting).statistical test confirmed that the different 14 speech productions scores between the groups was statistcally significant.teachers reports indicated academic delines(e.g,lower grades,increased failure to complete assignments)on average for'b'but not group'a'.in addition,according to teachers and staff members,children in group'b'exhibited an increase in behavioral problems,rule violations and verbal and physical fights with peers.the self-esteem scores for children in group'b'were significantly lower,on average,than the self-esteem scores for chldren in group'b'after the study was completed and all of the data had been collected,the graduate student visited with each member of the group'b'one more time to inform them that the conclusion that they were beginning to stuter had been inaccurate.