Multiple intelligence theory in multiple children: Twins and triplets

The aim of this dissertation is to investigate 6/7- 11/12 year-old 679 co-twins and 33 triplet siblings' multiple intelligence types in Turkish context and to find out how they differ in terms of birth order, zygote type, gender and grade level factors. The subjects, aged 7- 12 were chosen from the 1st and 6th grade levels, in 42 schools (21 Primary, 21 Middle schools) in Esenler/Istanbul during the Spring Term of 2014-2015 and the Fall Term of 2015-2016 academic years. The data of the study was gathered through two data collection instruments. The first data collection instrument was an adapted version of Shearer's (2007) "Multiple Intelligences Development Assessment Scales (MIDAS)" and the second one was a "Family Information Form". The analysis of the data obtained from 679 co-twins and 11 sets of triplets (712 children in total) tried to answer four research questions. The first research question aimed at investigating the relationship between birth order and multiple intelligence, and it was found that there was no statistically significant relation between birth order (Child A, Child B and Child C) and multiple intelligence types in twins and triplets. The second research question focused on analyzing the effect of twin types (zygote types) on multiple intelligence type, and it was found that fraternal/DZ twins had significantly higher scores on verbal/linguistic and musical intelligences than identical/MZ twins. However, zygote type was not considered and analyzed in triplet students since their zygote types were not known. The third research question was on the analysis of gender factor among twins and triplets and it was found that female co-twins had significantly higher scores on verbal, musical and inter-personal intelligences than male co-twins. However, male co-twins had significantly higher scores than female co-twins on mathematical intelligence. As gender factor was analyzed, no significant difference was found in triplet students. Last research question aimed at investigating the relationship between grade level and multiple intelligence in multiple children. It was found that there were significant differences at four intelligences in twins: mathematical/logical intelligence, kinesthetic/bodily intelligence, nature intelligence and intrapersonal/individual intelligence. At mathematical/logical intelligence,5th grade students had significantly higher scores than 1st grade students. At kinesthetic/bodily intelligence,5th grade students had significantly higher scores than 1st and 2nd grade students. At intra-personal/individual intelligence, 4th, 5th and 6th grade students had significantlyhigher scores than 1st grade students. At nature intelligence, 3rd, 4th and 5th grade students had significantly higher scores than 1st grade students. Among triplet siblings, it was observed that 6th, 5th and 4th graders have significantly higher spatial/visual intelligence scores than 1st graders. As a result, it was seen that even though twins were born together, their multiple intelligence rates and types were different from each other, and were affected by "twin type", "gender" and "grade level" factors but not by "birth order" factor. In triplets, it was found that there was a statistically significant relation between grade level factor and multiple intelligence types but not between gender and birth order factors and multiple intelligence types. Keywords: Twins, Triplets, Multiple Intelligences.