Yes. There are many variables that affect your heart rate. The most common ones are your cardiovascular health and genes.
Yes, the pulse rates of different locations should be the same since they are all coming from the heart.
It could be one person has already been exposed to that same fight or flight scenario and learned it was not a threat to their well being.
Of course. Heart rate is dependent on activity and the need of an individual body to exchange blood and/or cool down. Even if the twins are performing the same activity their heart rates could be different.
No, fingernails do not grow at different rates on the same hand. They do however grow at different rates on the more dominate hand.
It's kind of hard to explain but I'll try: It might be because they identify it as not a threat, causing them to react less (closer to normal heart rate) or they could realize it is a threat, causing their heart to beat faster. Also, some people seem to always be on edge and jumpy, like if you move suddenly they jump three feet in the air. Physical activity might be because they are already used to it, their body has adjusted and it doesn't affect them as much. This might not help much, but oh well, I tried.
a young persons heart is more recently fully developed giving it a peak advantadge over an old and used up heart
same thing
No,different soils absorb rainwater of different rates
Bank savings interest rates in the UK are pretty much the same as they are in the US. Different banks offer different interest rates, ranging from 4% to 12%.
There are lots of website that let you compare different insurance rates for the same trip. These websites include www.netquote.com/ and www.kanetix.com/.
No, different soils absorb rain water at different rates.
Rocks cool at different rates due to how they were formed if they were formed intrusively or extrusively Examples of different igneous rocks that form differently is Granite and Gabbro form the same but different from Rhyolite.