<a href=https://explorable.com/cause-and-effect>Establishing Cause and Effect</a>. Cause and effect is one of the most commonly misunderstood concepts in science and is often misused by lawyers, the media, politicians and even scientists themselves, in an attempt to add legitimacy to research.
You can't catch cancer from anyone, in any way. Cancer is not contagious. You can't catch HIV/AIDS just by touching somebody. The AIDS virus is not found in sweat. Yes, you can catch a cold, or the flu by shaking hands with someone if you then put your hands on/near a mucous membrane (eyes, nose, mouth).
One sibling could have a hand tremor and the other sibling might have a voice and head tremor, says Lewitt. It's often confused or even misdiagnosed as Parkinson's disease. But with essential tremor the shaking usually occurs when the person is doing an activity, like writing or lifting a spoon. People with Parkinson's shake when their hands are at rest. The other major difference is essential tremor does not typically worsen or progress to complete disability, like Parkinson's disease.