Question

3. What is the difference between reliability and validity? Can a test have one without the other? Is a person’s level of intelligence influenced more by heredity or environment?

Answer 1

Realiability is how consistent a test is, and whether it keeps generating the same results when the test is repeated. If a test keeps producing same or similar results then it is said to be reliable. Validity is mesurement of something which the tests is supposed to measure. If a test mesures what it aims to measure, it is said to be valid.

A test can be reliable but not valid, where the tests keeps generating same results upon repeated testing, but it is not measuring what it is supposed to measure. Also, the test can be valid but not realiable, where a tests is mesuring what it is supposed to measure, but there is no consistency in the results.

Heredity and enviornment both play a role role in intelligence. researchers believe that heredity is responsisble for placing a lower and higher limit on intelligence and enviornment determines the what the intelligence is going to be. Heritability of intellegence lies between 60% to 80% according to research. Twins studies have shown high correlation between identical twins IQ's, and other family studies also show similarity in IQs among family members. Enviornmental factors also play a role, such as children bough up in the same enviornment have similar IQ's, and children raised in deprived enviornment have lower IQ's.