The black line is the water line – with most of the iceberg below the water.  Most of our human characteristics are also hidden from view.  Just our behavior is visible above the water line.  As well as being instantly observable, behavior is also instantly changeable – you can stop doing one thing and start another. As you go down the chart – deeper under the water – the characteristics become more fixed.  For example, most psychologists and researchers seem to agree (roughly!) that around 70 to 80% of thinking preference is environmentally determined, with only 20 to 30% being hereditary. Personality would also seem to be more ‘fixed’ than thinking preferences. As you can also see from the chart, thinking preference is closer to and therefore has a more immediate impact on behavior which leads to lots of scope for development. Given that thinking preferences are more changeable and more closely related to behavior the NBI® would therefore be the better choice in a learning environment. Whereas in a Personality Inventory there is only an assessment there is no scope of learning and development within the inventory.