Many years ago I was at a theme park in southern CA and was enjoying from a front seat a jungle type float trip -- then we entered into a tunnel and before I knew it we were at the top of about a 90-foot waterfall-slide!!! They always take pics to sell you, so we got one that showed my wife screaming with her hands pumping in the air with joy and glee. Meanwhile, my knuckles are white from gripping the bar and my screams are sheer terror and panic.

From the view of the two-factor-theory of emotions what was going on in us that explains these widely differing reactions to the same external event?