What is the opposite of serio in spanish? Please help, I really need it!

"in english, write six to eight sentences comparing cultural aspects of greetings in spanish-speaking countries with greetings in your own culture. use what you learned in the lessons to tell about three differences and three similarities. discuss non-verbal greetings and how respect is shown. you may also include verbal greetings, but do not simply translate phrases from one language to another."