where did the term blood is thicker than water come from
Blood is thicker than water The equivalent proverb in German (originally: Blut ist dicker als Wasser), first appeared in a different form in the medieval German beast epic Reinhart Fuchs (c. 1180; English: Reynard the Fox) by Heinrich der Glîchezære. The 13th-century Heidelberg manuscript reads in part, "ouch hoer ich sagen, das sippe blůt von wazzere niht verdirbet" (lines 265-266). In English we read, "I also hear it said, kin-blood is not spoiled by water." which may in part due to the high seas being tamed refer to distance not changing familial ties or duties.
Body water By weight, the average human adult male is approximately 60% water and the average adult female is approximately 50%. There can be considerable variation in body water percentage based on a number of factors like age, health, weight, and sex. In a large study of adults of all ages and both sexes, the adult human body averaged ~65% water. However, this varied substantially by age, sex, and adiposity (amount of fat in body composition). The figure for water fraction by weight in this sample was found to be 58 ±8% water for males and 48 ±6% for females.[1] The body water constitutes as much as 73% of the body weight of a newborn infant, whereas some obese people are as little as 45% water by weight.[2] This is due to how fat tissue does not retain water as well as lean tissue. These statistical averages will vary with factors such as type of population, age of people sampled, number of people sampled, and methodology. So there is not, and cannot be, a figure that is exactly the same for all people, for this or any other physiological measure.