Environment and upbringing are considered to be just as crucial if not more so than genetic inheritance in a person's life-long development. (Photo: GT/Li Hao)
Xu Gelin, doctor of neurology at Nanjing General Hospital of Nanjing Military Command, noted in a Jinling Evening News report published in November 2014 that genetic heredity was highly complicated and random, and that both the mother and father had varying degrees of genetic influence on their child.
"For example, if the mother has a high IQ, and the father has a low IQ, their child will most likely be somewhere in the middle," said Xu, in direct contradiction to the claim in the Sina Weibo article that "one need only look to the mother" to know a child's intelligence.
"Of course, it is well accepted that a child whose parents both have high IQs will generally be quite smart."
Tall or short, good-looking or ugly?
The results of a study conducted by the Royal Devon and Exeter Hospital and Peninsula Medical School found that fathers have a greater influence on a child's height, whereas mothers have more of a child's weight.
The study looked at the height and weight of 1,150 children at birth, then again as 3-month-olds, 1-year-olds and 2-year-olds. Researchers found that taller fathers produce longer babies at birth, while a mother's body mass index (BMI) was the main determinant in a child's weight.
Xu said that genetic inheritance was a major factor in a person's height, but that it was more complicated than simply saying that a tall father will produce a tall child.
"In reality, 23 pairs of chromosomes combine randomly to determine a person's height and other physiological traits," said Xu.
"There are also instances where both parents are tall, but their child is short, or where both parents are short, but their child is tall."
Also affecting height, weight and other physical traits such as eye color and hair color, were whether particular genes passed down by mother or father were dominant or recessive, and how those dominant or recessive genes combined.
As an example, Xu said that the gene for double eyelids is dominant while the gene for single eyelids is recessive.
A child with one double-eyelids gene and one single-eyelids gene would have double-eyelids, but to have single-eyelids, the child would need to inherit the recessive single-eyelid gene from both parents.
A guokr.com report in 2011 noted that for Asians, curly hair is recessive whereas for most Caucasians, it is dominant.
There were also a number of other genetic processes that could affect a person's physiological make up, including complementation, overlap, suppression and mutation, said Xu.
"Beyond genetic factors like heredity and mutation, a child's personality, body height and eyesight are hugely affected by environmental factors, such as physical exercise, nutrition and upbringing," said Xu.
Environment and upbringing
It is widely accepted by scientists and experts that environmental and cultural factors play a major role in determining a child's development, particularly as he or she reaches adulthood.
"I've always prescribed to the old Chinese saying: 'Do one's level best and leave the rest to God's will,'" said Zhao.
"We should know what we already have inherited, among which are unchangeable parts and changeable parts. We make good use of the unchangeable parts, and try to improve those changeable parts by cultivating our potential through the optimal environment."
While there have been studies investigating the role of genetic inheritance in a child's personality, Xu said that there was no consensus on the degree of influence genetics had, and that in his opinion, a child's upbringing played an even more significant role in shaping personality and intelligence.
"During a child's development, he or she automatically learns from and imitates the people closest to him or her," said Xu.
"When we say that a child's personality is more like the father's or mother's, it is simply a case that the child has imitated that particular parent more closely."
