Why doesn't Chef use my default attributes in my development environment?

I inherited our company's Chef repository and I'm learning as I go. One issue that I've found a workaround for (but would like to understand or avoid if possible) is that attribute defaults specified in cookbooks are not available to nodes in my development environment. So to get these things that work fine in production to run in development, I have to make a change like so:

Works in production

default[:webservices][:debug] = "False"
default[:webservices][:template_debug] = "False"

Works in development

set[:webservices][:debug] = "False"
set[:webservices][:template_debug] = "False"

Going forward, I want to be able to specify a default and then override it for development, say to use development database settings, etc. with the same templates. Why isn't the default accessor working in development? I can provide more configuration details upon request.