How Big is a Human Brain?

Size and Weight: - An adult human brain's weight ranges from 1300 to 1400 grams (approximately 3 pounds). - A newborn baby's brain weighs around 350 to 400 grams (three-quarters of a pound). - Dimensions: 5.5 x 6.5 x 3.6 inches (140 x 167 x 93 mm).

Interesting Facts: - The brain constitutes 2% of a human's body mass, while the shrew's brain is around 10%. - Sperm whales and elephants have the largest brains in terms of weight, at 18 and 11 pounds, respectively. - The human brain reaches full formation by age 25, developing from back to front. - Males tend to have larger brains than females, with a difference of about 100 grams after considering body weight. - Brain regions like the frontal and limbic cortex are larger in women, while men have a larger parietal cortex and amygdala. - The human brain consists of an estimated 86 billion neurons transmitting information.

Intelligence and Brain Size: - Correlation between brain size and intelligence has been debated. - Studies have inconclusive results, with other factors like neuronal density and social influences playing a role. - Brain size variations are relatively small among humans.

Conclusion: Brain size is just one factor in determining intelligence and various aspects of human cognition.