I feel that an interesting way to percieve Gabriel and Langs theories would be through the looking-glass of the nature/nurture debate. I feel that, as mentioned by others, nature - ie specific behavioural and personality traits may be fixed within us - again drawing back to the notion that a leapord can't change its spots.
Since identity is an ever-evolving project, an unfinished narrative, there is never a way to accurately quantify it, and there will never be a way of finitely asserting the varying degrees to which specific elements of individuals identities are collated from individual sources.
I believe that it could be argued that in this postmodern capitalist society, attempts have been made by many to break away from the norms of consumerism; movements such as 'occupy', and other anti-consumerist movements have become almost commonplace. It could even be asserted that for some people, objects which are percieved as embodying a higher moral, ethical, or personal value could then hold more sway in regard to identity than those which are increasingly being presented as meaningless and as facilitating inequality and poverty across the globe, and therefore falling into categories of negative schematisation for some. Others however, may be more willing to accept the inequalities of the world we live in, and percieve campaigns such as Adbusters 'Buy Nothing Day' as pointlessly anti consumerist; though it is my opinion that people who chose to adopt such view may find it subject to change over time, making phenomena such as an 'identity crisis' more likely should such views eventually become underwritten by the discovery of specific contributants to identity which embody a higher level of moral, ethical or personal value.