Depending on what you find you have a variety of alternatives open to you. Perhaps one of the following ideas will prove useful for your department as it strengthens its curriculum. Require that your majors take additional General Education math and science courses. This was almost always one more mathematics course. The issue of statistics, reaching your average student with a psychology major in this course, and the person who teaches it keeping his or her sanity would require a complete symposium in its own right, and is an important one.
Some departments require computer science for their majors.
Departments may require that its majors take biology to meet the science requirement, for example. This approach views such restrictions as providing either preparation for psychology majors, or courses that complement and therefore, improve the quality of education as a major. Have majors demonstrate proficiency in General Education. If your department is concerned about students, theoretically, learning what they need to learn, require they demonstrate such. Some require that certain courses be completed and that a certain overall GPA be obtained.