Answer To: Sheet1 Right arm:Left arm: SexAgeAngle (°)Angle (°) Individual 1F221118 Individual...
Rajeswari answered on May 16 2021
From the class data posted (see google doc links) present your summary of the data below. You should plot mean values (+/- standard error of the mean) for each group. Your summary data should compare sex and age where appropriate. You figures should be supported by a concise and informative legend:
Digit Ratios (15 marks)
2d: ratio
Mean
10.859220287
Std error
0.002562335
Hence we get 10.859±0.00256 = (10.8567, 10.8618)
Carrying Angles (15 marks)
Right arm (angle)
Left arm (angle)
Mean
13.4873
Mean
13.47588
Standard Error
0.282532
Standard Error
0.281874
Hence we write as
For right angle
13.4873±0.2825 = (13.2048, 13.7698)
For left angle
13.4759±0.2819=(13.1940, 13.7578)
How do the 2D:4D digit ratios compare? Are they what you would expect? You should refer to at least two primary research articles from the scientific literature to support your argument. (15 marks)
We expect that 2D:4D digit ratios would be equal for males and females or ages.
From a study of 136 males and 137 females at the University of Alberta:[32]
· Males: mean 0.947, standard deviation 0.029
· Females: mean 0.965, standard deviation 0.026
Observed values are:
Mean
1.978479661
1.930562614
Std dev
0.049857313
0.050001882
n
250
148
These are very much different from the expected as in the internet articles.
1. Mayhew TM, Gillam L, McDonald R, Ebling FJ (November 2007). "Human 2D (index) and 4D (ring) digit lengths: their variation and relationships during the menstrual cycle". Journal of Anatomy. 211 (5): 630–638. doi:10.1111/j.1469-7580.2007.00801.x. PMC 2375787. PMID 17764524.
2. ^ Jump up to:a b c Kumar, Sanjay; Voracek, Martin; Singh, Maharaj (6 March 2017). "Sexual Dimorphism in Digit Ratios Derived from Dorsal Digit Length among Adults and Children". Frontiers in Endocrinology. 8: 41. doi:10.3389/fendo.2017.00041. ISSN 1664-2392. PMC 5337486. PMID 28321205.
3. ^ Jump up to:a b c Auger, J.; Eustache, F. (August 2011). "Second to fourth digit ratios, male genital development and reproductive health: A clinical study among fertile men and testis cancer patients: Finger ratios and male reproductive health". International Journal of Andrology. 34 (4pt2): e49–e58. doi:10.1111/j.1365-2605.2010.01124.x. PMID 21091719.
Briefly, what, if any, is the endocrine basis for sex/age differences in digit length ratios? You should refer to at least two primary research articles from the scientific literature to support your argument. (20 marks)
Digit lengths increased with age and tended to be longer in males but did not differ with hand preference. In the right hand, there were significant age (P<0.01), gender (P<0.001) and hand preference (P<0.05) effects on the 2D:4D ratio and a significant age×gender interaction (P<0.05).
· The ratio of 2nd to 4th digit length: a predictor of sperm numbers and concentrations of testosterone, luteinizing hormone and oestrogen.[Hum Reprod. 1998]
· Scientometric analysis and bibliography of digit ratio (2D:4D) research, 1998-2008.[Psychol Rep. 2009]
· On the relation between 2D:4D and sex-dimorphic personality traits.[Arch Sex Behav. 2008]
2D:4D ratios of males and females show a difference of 0.047900. To check whether this is significant at 5% level, we create hypotheses as:
H0: averge of females = average of males
Ha: averge of females ≠average of males
(Two tailed test)
The two-tailed P value is less than 0.0001
By conventional criteria, this difference is considered to be extremely statistically significant.
(Refer excel sheet for data sorting between males and females)
By previous hypothesis we found that there is a significant difference in digit length ratios of males and females
Let us check agewise
For this we sort the original data according to age and group it.
The scatter plot of age vs 2D:4D ratio is almost horizontal. This means that 2D:4D ratio is not dependent on age.
i.e. the ratio depends on the sex significantly but not dependent on age.
How do the carrying angles compare? Are they what you would expect? You should refer to at least two primary research articles from the scientific literature to support your argument. (15 marks)
When your arms are held out at your sides and your palms are facing forward, your forearm and hands should normally be about 5 to 15 degrees away from your body. This is the normal "carrying angle" of the elbow. This angle allows your forearms to clear your hips when you swing your arms, such as during walking
The carrying angle is...