What is the mindset Professionals should have towards less performing individuals?

In one word - "EMPATHY". To elaborate further it is definitely important that you try to figure out the reason behind lack of performance. There may be various factors involved, trying to address these issues are a must especially if you are a leader as that's what leaders are expected to do. Some amount of hand holding may be necessary. If this works then you have performed as a true leader. Even after all this if you fail then do not feel let down by your own self. The individual may be incapable of delivering on this particular job so that's when you need to take a call and reassign him to something which he is suited for if at all that is possible otherwise as a professional you have to escalate the matter as the team performance will suffer it you do not take steps. 

     فهم علم النفس والوصول إلى السبب الجذري لماذا هو أقل أداء ... لأن كل شخص لا يحمل نفس الخصائص. تأكد من أنه لا يمر بأزمة شخص في المنزل / خلاف ذلك.     تزويدهم بالمهارات المناسبة أو التشجيع: بعد التأكد من سبب ذلك ، من المهم معرفة ما إذا كان / هي يتمتع بالعمل ، أو لديه مهارات كافية لأداء الوظيفة أم لا؟ إذا لم تفعل ذلك ، فستكون مهمة مدير الأشخاص هي تمكينه / لها من المهارات المناسبة أو منحه الوقت الكافي لالتقاط المعرفة المطلوبة للقيام بذلك.     التحول نحو أقل أداء الأشخاص إلى الأصول الحقيقية: بشكل عام ، من الأفضل أن يعتني به لأداء درجة معينة من التحديات ، والتي من شأنها أن تكون أفضل طريقة للتعامل مع الأفراد الأقل أداءً ، وتحويلهم إلى أشخاص طيبين يساهمون في مشروع / برنامج.

• inspire individuals to do what is right,
• you can guide them along the way and be a good model to follow,
• you can monitor their progress in every step. Being able to lead a group and manage these individuals in a way that does not impede their progress and insult their judgement is highly desirable in today’s workplace.
• Integrity and well-founded moral values should be highly-respected in the work place. 
• be good listener.
• upgrade the skile of your employee if they need.

The same mindset when your family member comes with fewer performance marks. out of 24 hours, approx 10 hours a day is spent at work so its vital that what we make our work life and team members off.

I may be wrong but I have my own parameters like researchers have their own way of research. 

The mindset should be clear and directive towards less performers everyone has its own capacity and you have to deal with everyone separately but through a series of coaching and guidance, it may help nonachievers to achievers. 

Coach them, guide them, make them comfortable once you achieve that goal may be the person you are dealing with can achieve their goal. It's a two-way game/process.

I understand less performers must be subject to conselling, guidance, regular interaction, evaluation and feedback and support. If job knowledge is the barrier then TNA with workable individual development plan need to put in place. Less performance can be expected with freshers for various reasons. Superiors careful handling will resolve most of the problems in regular cases. If the less performance is due to employee poor attitudes towards work, lateness and personal engagements HR has to refer to ER for disciplinary action. Under any circumstance less performance should not be left unattended which will tend to affect colleagues

positive mindest is important. They should be given time with trainings (if needed) or sometimes just boosting the moral helps.

It starts with a proper TNA. The problem is always a secondary thing, we need to identify the root cause creating that problem. It could be done through different ways;

1. proper analysis.
2. get yourself ivolved in the process.
3. behaviour change analysis and many more..

You can provide them challenges with authority.

Employees work more efficiently when they are giving autonmy and free ground to play

No procedure can work out unless they feel comfortable and easy with it.