Some research suggests that first born children may have higher IQ scores than their later born siblings. Do first-born identical twins have higher IQ scores than their second-born sibling? Data from a 1998 study were analyzed to determine whether first-born identical twins have higher IQ scores than their second-born siblings. Ten pairs of adult identical twins were assessed and their Full Scale IQ scores were calculated.Source: M. J. Tramo, W. C. Lodtus, T. A. Stukel, R. L. Green, J. B. Weaver, and M. S. Gazzaniga. “Brain Size, Head Size, and Intelligence Quotient in Monozygotic Twins.” Neurology 50, 1246–52.The following hypotheses were tested:H0: μd = 0Ha: μd < 0The following is the (edited) output for the test:SampleNMeanStDevSE MeanFirst-born10112.914.74.65Second-born10108.711.33.57Difference104.113.44.2395% lower bound for mean difference: −4.36t-test of mean difference = 0 (vs. > 0): t-value = 0.97, p-value = 0.179Which of the following is an appropriate conclusion based on the output? The data provide sufficient evidence to reject H0and, thus, conclude that the mean Full Scale IQ score for first-born identical twins is higher than the mean Full Scale IQ score for second-born identical twins. The data do not provide sufficient evidence to reject H0. We therefore conclude that the mean Full Scale IQ score for first-born identical twins is higher than the mean Full Scale IQ score for second-born identical twins. The data provide sufficient evidence to reject H0. We therefore conclude the data do not provide evidence to conclude that the mean Full Scale IQ scores for first-born identical twins is higher than that of second-born identical twins. The data do not provide sufficient evidence to reject H0. In other words, based on the data we cannot conclude that the mean Full Scale IQ scores for first-born identical twins is higher than the mean Full Scale IQ score for second-born identical twins.

Similar intelligence test scores for identical twins reared apart are taken as evidence for the:

Identical twins who were brought up in dramatically different social environments score quite differently on intelligence tests. This supports which of the following?Multiple choice question.the impact of socialization on human developmentthe influence of heredity on intelligencethe impact of "nature" on intelligencethe failure of environmental factors to influence intelligence

Research suggests that identical twins have many similarities, such as body weights, even as adults. A sample of ten sets of identical twins were weighed and had their weights recorded in kilograms. The researcher wishes to test whether there is a statistically significant difference in adult weight between first-born and second-born identical twins.Source: M. J. Tramo, W. C. Lodtus, T. A. Stukel, R. L. Green, J. B. Weaver, and M. S. Gazzaniga. “Brain Size, Head Size, and Intelligence Quotient in Monozygotic Twins.” Neurology 50, 1246–52.Given the design of the study and the question of interest, which one of the following computer outputs is relevant to use?

The observation that each generation has a significantly higher IQ than the last is called:Question 2Select one:a.Generation biasb.IQ biasc.Testing effectsd.Flynn effecte.None of the above

The evidence for hereditary influences onintelligence comes mainly from studies ontwins and adopted children. Theintelligence of identical twins rearedtogether correlate almost 0.90. Twinsseparated early in childhood alsoshow considerable similarity in theirintellectual, personality and behaviouralcharacteristics. The intelligence of identicaltwins reared in different environmentscorrelate 0.72, those of fraternal twinsreared together correlate almost 0.60, andthose of brothers and sisters rearedtogether correlate about 0.50, whilesiblings reared apart correlate about 0.25.Another line of evidence comes from thestudies of adopted children, whichshow that children’s intelligence is more