A biologist would probably plot brain mass vs body mass to estimate intelligence. It is not just the size of the brain that determines intelligence. You run into problems trying to compare different species. Humans are terrestial bipeds who spend a lot of time studying and manipulating their environment. We communicate through speach and have developed a complicated social structure. Dolphins are air breathing aquatic swimmers that are active much of the time. Acoustic information is relatively more important in forming world view and how they interact with it and among themselves. They are social but live in small groups. The social structure is not as highly developed. Dolphins display a lot of cooperative activity. They are not only aware of their own needs but those of others too.

Most of the brain seems to be devoted to subconscious activity such as processing and storing information. It is more difficult to say how much is needed for conciousness or awareness. Living in an open environment may require more "bandwidth" for a larger attention span. More brain might be needed to accomplish this task.

Leisure time is also necessary for the developement of higher intelligence. It takes time to learn from experience and acquire knowledge. How much free time do dolphins have for this? Is dolphin developement preprogramed genetically or influenced by environment? The nature or nurture question needs to be answered for dolphins too. An animal who's developement was more dependent on interaction with its environment would probably possess greater adaptability and individual intelligence.

Sorry to hear about the ADHD. I have a sister with a similar problem.

• Sound processing uses a lot of "instrumentation" - kantolfir2 - September 8, 2003 - 19:14 UTC